摘要:

2406 EWINS: NARCISSINE: A N ALKALOID FROM THE BULB OFC1CXLV.-i~'c~ilcissi~?.r! : c i t b Alkcdoicl f m m the Bull, ofthe ConmmL Dafodil (Narcissies psewhara'ss.zcs).By ARTaun JAMZS &+-INS.IN 1878 a paper was published by Ringcr and Morshead ( J . P?ipiol.1, 437), entitled " On the physiological action of narcissia, analldoid obtained from the bulb of thc connuon daffodil (Sarcissrrspseuclonarcissua)." This work contained a detailed .account ofexperiments carried out on men and frogs with an alkaloid or withextr<acts cont,a.ining the alkaloid, which had been obta.ined byGorra,rd from the bulb of the common daffodil. From experimentscarried out with extracts obtained from bulbs in the resting &ageand from bulbs of t,he flowering p h t s , the authors concluded thatthe adion of the alkaloid prownt in t,he extracts from the resthgbulbs was similar to that of pilocarpine, whcreas that present inthe extracts from the bulbs of the flowering plants closely resembledatropine in action.The a.lka.loid obtained by Gerrard from bothextracts nevertheless a.ppearcd to be tlic same in general chemicalpropertiesTHE COMMON DAFFODIL (NARCISSUS PSEUDONARCISSUS). 2407I n view of these statements and of the fact that no reference to“narcissia” or to any alkaloid obtained from the bulbs of thedaffodil can be found in chemical literature, it appeared to be ofinterest to obtain the alkaloid in a pure state, in order that a moredetailed investigation of its chemical and physiological propertiesmight be made, more especially as the alkaloids which have beenobtained from monocotyledons are comparatively few in number.The bulbs of a cultivated variety of the daffodil (A7arciss?6Sprinceps), being more readily obtainable than the variety mentionedabove, were first employed in the investigation.From these bulbs,however, the extracts obtained from the resting or flowering bulbsgave only traces of alkaloidal reactions, and the isolation of thealkaloid was obviously hopeless. With t h e h l b s of the wild daffodil(Narcissus pseudonarcissus), much more satisfactory results wereobtained. From these a crystalline alkaloid was readily obtained.From the resting bulbs a yield of approximately 0.2 per cent. ofthe dried material, and from the flowering bulbs only about 0.1per cent., was obtained.The alkaloid, which, in accordance withmodern usage, it is suggested be called “narcissine,” rather than“ narcissia,” was the same in both cases.Narcissine has been found by analyses and molecular-weightdetermination to possess the formula Cl,H170,N;. The alkaloid ischaracterised by very great stability, and on that account) andowing to the small amount of material available (about 3 gramsonly), no light has been thrown on its probable constitution. Tlienitrogen present is tertiary, since nitrous acid is without action onthe alkaloid, and treatment with methyl iodide produced anamorphous product which was probably the methiodide of the base,but which could not be crystalljsed for analysis.The action ofhydriodic acid (Zeisel) showed the absence of methoxy-groups, buton very strongly heating, a very small amount of methyl iodidewas evolved, and the residue on suitable treatment yielded a solutionwhich gave a violet coloration with ferric chloride, the phenolicsubstance being extracted from its acid solution by ether. Theamount of substance so obtained was, however, extremely small, andfurther attempts to hydrolyse by means of acids yielded nocrystalline product.A ttemperatures up to 220° the alkaloid was only very slowly attacked,traces of alkaline vapour being evolved. Heating with the nakedflame for one and a-quarter hours was required in order to decomposecompletely about 0.7 gram of the alkaloid. The reaction productdissolved in water gave on addition of ferric chloride a violetcoloration, quickly passing to it dirty brown, with separation of a,Fusion with potassium hydroxide yielded no better results.7 s 2408 EWIN3: NARCISSINE: AN ALKALOID FROM THE BULB OFbrown, fiocculknt precipitate.This polyphenolic substance, again,could be extracted by ether from its acid solution, but on evaporatingoff the solvent only a very small quantity of a brown, amorphousproduct was obtained, and all attempts to obtain a crystallineproduct were fruitless.On account of the relatively large number of oxygen atomspresent in the molecule, it was thought possible that a carboxylgroup might be present, but attempted esterification showed theabsence of such grouping. For this reason and from the absence ofmethoxy-groups as shown by the Zeisel reaction, the formation ofa polyphenolic derivative such as has been described is very possiblydue to the presence in the molecule of a methylenedioxy-groupingand a phenolic bridge oxygen. The stability of the alkaloid wouldseem to support such a view, although there is, of course, no directevidence of such structure.Experiments with regard to the physiological action of thealkaloid were carried out in these laboratories by Dr.P. I?. Laidlaw,to whom I am indebted for the following account of its action.As tested on frogs and cats, the alkaloid showed no action in anyway similar to that of pilocarpine or of atropine. 0.125 Gram,given by mouth to a cat, caused nausea, vomiting, salivation, andpurgation.The salivation was not, however, similar to that producedby pilocarpine, since it could not be produced on the anaesthetisedanim a1 .EXPERIMENTAL.Preparation of the Alkuloid.Two thousand five hundred bulbs of the common daffodil(Narcissus pseudonarcissus), weighing approximately 4 kilos., weredried at a temperature of about 40°. The weight of the driedproduct was 1400 grams. The substance was finely ground andextracted for about six hours with hot alcohol (97 per cent.), a-ndthe alcoholic extract evaporated to about 200 C.C. To the darksyrupy, acid liquid was added an equal volume of water, and avery dark resinous precipitate which formed was collected. Thisprecipitate was re-suspended in a little very dilute acid, and againcollected after thoroughly shaking.The filtrate and washings werecombined, and the acid liquid extracted twice with about one-thirdof its volume of ether. The aqueous solution was then renderedalkaline by addition of sodium carbonate, when, after some time, aprecipitate formed, which consisted mainly of bunched prisms. Thecrystals were collected, and after recrystallisation from 90 per cent.alcohol were obtained as colourless, short, stout prisms, melting a t266-267O (bath at 250° at commencement of heating). The sub-stance was dried first in air, then in a vacuum over sulphuric acidTHE COMMOX DAFFODIL (NARCISSUS PSEUDONARCISSUS). 2409and finally at llOo, no alteration in weight taking place underthese varying conditions :0.1448 gave 0.3552 GO, and 0.0754 H20.C = 66.9 ; H = 5.8.0.1283 ,, 0.3159 CO, ,, 0'0684 H20. C=67'1; H=5.9.0-1051 ,, 5.0 C.C. N2 (moist) at 13'5O and 732 mm. N=5.4.C,,H,@,N requires C = 66.9 ; H = 5.9 ; N = 5.0 per cent.A determination of the molecular weight was made by Barger'smicroscopic method (Trans., 1904, 86, 286) in glacial acetic acid.0.060 Gram, in 1.197 grams of solvent, was intermediate between0.19 mol. and 0.20 mol., whence M.W. = 257. Cl6€Il7O,N requiresM.W. = 287.Properties of Narcissine.-The alkaloid, as before stated, isobtained by recrystallisation from alcohol in colourless prisms,which melt at 266-267O with some decomposition and formationof a red liquid. Tke crystals are insoluble in water or dilute sodiumhydroxide, but readily soluble in dilute acid.The acid solutiongives all the usual alkaloidal reactions, for example, with Meyer'sreagent, with a, solution of iodine in potassium iodide, and withphosphotungstic acid. The crystalline product is only verysparingly soluble in methyl alcohol, ethyl alcohol, ethyl acetate, oracetone, moderately so in pyridine, nitrobenzene, or glacial aceticacid, and insoluble in ether or chloroform. A determination of itssolubility in absolute ethyl alcohol showed that one part by weightof the alkaloid was soluble in 284 parts of boiling alcohol and in340 parts of alcohol at 15O.0.166 Gram, made up to 100 C.C.with absolute alcohol, gave, in a 2.2-dcm. tube at loo, a, -0*35O,whence [a] 2 - 95.8O.The alkaloid dissolves in concentrated sulphuric acid, producinga deep red solution, which slowly becomes reddish-brown on keeping.Narchissine Hydrochloride, Cl,Hl7~,N,HC1.-@3 Gram of crudenarcissine was dissolved in dilute hydrochloric acid, and the solutionevaporated to dryness over potassium hydroxide in a desiccator.The resulting crystalline product was dissolved in hot 90 per cent.alcohol, and after treatment with a, little blood-charcoal, the solu-tion, on cooling, deposited the hydrochloride in long, thin prisms,melting at 198-199O.The alkaloid is lzvorotatory.Yield, 0.27 gram :0.2737 gave 0.1176 AgCl. C1=10*6.C,6H,704N,HC1 requires c1= 10.9 per cent.THE WELLCOME PHYSIOLOGICAL RESEARCH LABORATORINS,HECNE HILL, S.E

ISSN:0368-1645    

DOI:10.1039/CT9109702406

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2410 MARSH: THE ACTION OF HALOGENS ONCCXLVL- The Action of Halogens on MercuricamphorCompounds.By JAMES ERNEST MARSH.THE work described in this paper is a continuation of that publishedby Mr. Struthers and the author on the mercury derivatives ofcamphor (Trans., 1909, 95, 1777).I n the former paper it was shown that di-iodoca.mphor wasobtained by the action of iodine on one of the mercury derivatives.It is now found that the same di-iodocamphor is formed from thethree mercury compounds, namely, those which have the formuk :of preparation is the same in each case The mercury compound istreated with an aqueous solution of iodine and potassium iodide,enough iodine being taken to combine with the mercury and thecamphor residue, and enough potassium iodide to hold the mercuriciodide in solution.The product of the reaction is extracted withchloroform, and the chlorof orm solution washed with sodiumhydroxide, dried, and rapidly evaporated. The di-iodocamphor isthen left in the crystalline form, and, after washing with lightpetroleum, is practically pure. A small amount of camphor-quinone, which is formed, is removed by the petroleum. If theoperation is carried out carefully, the yield is nearly quantitative,but if the substance is left too long in the chloroform solution theamount obt'ained is less satisfactory, as it decomposes in solution.Even when the substance is partly decomposed by being overheatedor left too long in solution, a good product can still be obtained byboiling with sodium hydroxide solution, and washing the residuewith petroleum.Di-iodocamphor, when in solution, rapidly decom-poses with separation of iodine. I n order to recrystallise it, the bestsolvent was found to be aqueous pyridine. It is very soluble inpure pyridine, and, on adding a little water, crystals at onceseparate. The crystals should be spread out in a thin layer to dry,as they rapidly decompose if heaped up in masses while still wetwith the solvent. The compound decomposes a little above itsmelting point, 108O, with evolution of iodine. It is stable inpresence of alkalis, and may be kept under a solution of sodiumhydroxide. It may be boiled with aqueous sodium hydroxide with-out decomposition, and it is not appreciably volatile in steam.C1()H140Hg212, (c10H140)3Hg412, and (c1(1H140)4H&12' The methoMERCURICAMPHOR COBIPOUNDJ. 241 1A ction of Oxygen on Di-iodocamphor.Camphor quinone.Although in the crystalline form, di-iodocamphor is stable whenexposed to air, when dissolved in chloroform it decomposes withseparation of iodine. One atom of oxygen takes the place of thetwo atoms of iodine, and camphorquinone is formed, along with asmall quantity of camphoric anhydride.To obtain camphorquinons in this way, air dried by sulphuricacid is bubbled through a solution of di-iodocamphor in chloroform.Iodine at once begins to separate, as is shown by the change in thecolour of the solution. Fresh chloroform is added, when necessary,to make good the loss by evaporation. When the action is finished,the product is mixed with a solution of sodium hydroxide anddistilled in a current of steam.The alkali serves not only to combinewith the free iodine, but also to convert the camphoric anhydrideinto sodium camphorate; otherwise the anhydride distils over inthe steam, and renders the quinone impure. The quinone appearsin the distillate as yellow crystals, and also colours the water yellow.It is extracted with ether or, better, with chloroform. The etherealextract gave, on evaporation, cryst*als melting at 196--197O, which,after recrystallisation from alcohol, melted at 198-199O. (Found,C=71*7; H=8*4.The yield of camphorquinone by this method is more than 90 percent. of that required by theory. This method should serve for theproduction of camphorquinone in any quantity from camphor, sincethe yield of the mercury compound from camphor and that ofdi-iodocamphor from the mercury compound are both nearlyquantitative.Further, all the mercury and iodine employed in thereactions can be recovered in the form of mercuric iodide, and usedagain for the preparation of the camphor-mercury compound.Camphorquinone is readily oxidised to camphoric acid by warm-ing with a solution of sodium peroxide; the crystals dissolve, andthe yellow colour of the solution disappears ; on acidifying,camphoric acid, melting at 186O, separates. It is converted bythe action of acetyl chloride into camphoric anhydride, meltingat 220O. This conversion of di-iodocamphor into camphorquinoneand camphoric acid shows that the iodine has replaced the hydrogenin the CH, group, which is adjacent to the CO group.It alsoshows further that, in the mercury derivatives, the Hg” and(HgI)’ groups are similarly situated in the ad-position. This wasanticipated by Mr. Struthers and myself from the circumstancethat the only ketones which we found to give mercury derivativeswere those having hydrogen in the a-position. The structuralCslc., C=72.3; E=8.4 per cent.2412 ACTION OF HALOGENS ON MERCURICAMPIIOR COMPOUNDS.relat,ionship of the mercury and iodine derivatives to camphor-quinone is shown by the lormulze:CHg T'sH14<&) ''Dimercuricamphor di-iodide. Di-iodocamphor. Cam phorquinone.Action of Bromine o n tlbe Mercu&anzphor Compounds.aaf-Di3 rornocamphor.The action of bromine on the mercuricamphor compounds is notso simple as is the action of iodine.I n the main, the reactionproceeds with the production of ad-dibromocamphor, melting a t6 1 O . The action is, however, complicated by liberation of iodineand its action, also by the oxidising action of the bromine, andfurther by the action of the hydrogen bromide produced in theoxidation.To prepare ad-dibromocaniphor, the mercury compound(C,,,Hl~0),Hg,12 is preferably employed, since it contains less iodinethan the other mercuricamphor compounds.The mercuricamphor compound is mixed with half its weight ofpowdered mercuric oxide, and this mixture is a.dded gradually toa solution in water of the requisite amounts of bromine andpotassium bromide, so that the whole of the mercuric bromideformed is dissolved in the water.The mixture is stirred all thetime with a turbine, and it becomes warm as the reaction proceeds.When cold, the mixture is extracted with chloroform. The chloro-form solution is washed with sodium hydroxide and water, dried,and evaporated. The crude dibromocamphor left on evaporation ispurified by solution in light petroleum. The petroleum solution isfiltered, i f necessary, from a small quantity of a crystalline sub-stance, which is referred t o later. On evaporation of the petroleum,the residue is distilled under diminished pressure. ucd-DibromWcamphor distils at about 175O/20 mm., and solidifies in the receiver.After recrystallisation from alcohol, it melted at 61O.(Found,Br =51*5.Mr. T. V. Barker examined the crystals with the goniometer,and found the measurements to be identical with those given byZepharowich for ad-dibromocamphor.By its production in this way, the dibromocamphor is broughtin t o relationship with di-iodo c amp hor , damp hor quinone, and cam-plioric a-cid ; hence its constitution as an aa'-compound is confirmed.The same dibromocamphor is produced by the action of brominein chloroform instead of aqueous solution. It is also obtained fromthe mercury compound C,,,HI,OHg,I,, and by the action of bromineon di-iodocamphor in chloroforin solution. It may be presumedCalc., Br =51-6 per cent.ACTION OF SODIUM AMAI,CIARI ON hIETHYLENE ETHERS. 2413to be also obtainable, like di-iodocamphor, from the intermediatemercury compound ( CloH140)3Hg412.The use of mercuric oxide in the preparation of dibromocamphorneeds some explanation.It was found to prevent the formation ofby-products. It probably acts by combining with any hydrogenbromide which may be formed, and thus preventing the decom-position of the mercuricamphor compound into camphor andmercuric bromide.The crystalline compound insoluble in petroleum is obtained whenmercuric oxide is not employed in the reaction; and at the sametime some a-monobromocamphor is formed. The former substancecrystallised well from alcohol, and melted a t 1 5 9 O . Numerousanalyses were made of this substance, prepared under varyingconditions. The analyses do not indicate the presence of a singlesubstance, but of a mixture intermediate between the compoundsCl,H,,0,Br2 and Cl0Hl4O,I2, with no simple relation between thebromine and the iodine atoms. When bromine acts on di-iodo-camphor, a similar substance is formed with relatively more iodineand less bromine in its composition, and of a higher melting point,namely. 1 7 2 O . A product of a similar nature is obtained withchlorine taking the place of bromine, when a chloroform solutionof di-iodocamphor is acted on by chlorine.When the mercuricamphor compound is treated with iodinebromide, IBr, or by iodine chloride, IC1, the principal product ineach case is di-iodocamphor.I wish to thank my assistant, Mr. F. Eall, for his excellent helpin this investigation.UKITERSITY LABORATORY,OXFORD

ISSN:0368-1645    

DOI:10.1039/CT9109702410

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

ACTION OF SODIUM AMAI,CIARI ON hIETHYLENE ETHERS. 2413CCXLVII. - Action of Sodium Amalyam on Meth ylerieEtlzei-s.By ARTHUR HENRY SALWAY.IN the course of the author’s previous investigations, which ledt o the synthesis of cotarnine (Trans., 1909, 95, 1204; this vol.,1208), the reduction of 3-methoxy-4 : 5-methylenedioxycinnamicacid (I) was described. In this reaction it was observed that thonormal reductdon product, namely, P-3-methoxy-4 : 5-methylene-dioxyphenylpropionic acid (11), was invariahly accompanied by aconsiderable proportion of a by-product. This substance, of whic2414 SALWAY: ACTION OF SODIUMno account was given in the previous communications, has now beenisolated in sufficient quantity to render its complete examinationpossible.The purified compound was found to possess the propertlies of aphenol and of a carboxylic acid, and gave analyses correspondingwith the empirical formula C,,H,204.It is evident that the p r eduction of such a compound from 3-methoxy-4 : 5-methylenedioxy-cinnamic acid (I) can only be explained by the simultaneousreduction of the aliphatic side-chain and the substitution of ahydroxyl group for the methylenedioxy-complex. The constitutionof the resulting compound would therefore appear to be representedby one of the two formulz A and B :OM0(1.)/\CH~-CH,-CO,Hor HO\/ I IOMe(B.)I n order to decide between these formulq the substance wasconverted by means of methyl sulphate into a dimethoxyphenyl-propionic acid, which melted at 61-62O. The dimethoxy-acidcorresponding with B, namely, P-3 : 4-dimethoxyphenylpropionicacid, melts, according to Tiemann and Nagai (Ber., 1878, 11, 653),at 97O, whilst the 3 : 5-dimethoxy-acid corresponding with A doesnot appear to have been hitherto described.Formula B is thusshown to be inadmissible, and consequently A most probably repre-sents the constitution of the substance under examination. Positiveevidence in support of this conclusion wits obtained by convertingthe dimethoxypropionic acid into the corresponding dimethoxy-benzoic acid by oxidation with alkaline permanganate solution.The product of oxidation melted at 180-181°, and was found tobe identical with 3 : 5-dimethoxybenzoic acid. It is thus shownthat in the reduction of 3-methoxy-4 : 5-methylenedioxycinnamicacid (I), the normal reaction is accompanied by a secondary changeinvolving the disruption of the methylenedioxy-complex and theformation of P-5-hydroxy-3-methoxyphenylpropionic acid (111),according to the scheme on p.2415.It was next deemed of interest to ascertain whether othermethylene ethers are capable of undergoing a similar change, andaccordingly piperonylacrylic acid (IV) was subjected to the actionof sodium amalgam. In this case, also, it was found that reductioAMALGAM ON METIIYLENE ETHERS. 2415takes place with partial conversion of the methylenedioxy-complexinto a hydroxyl group, the products of the reaction being a qixture(11.)HO/\CH,*CH,~CO,Hand 0 OMe(111.)of p-3 : 4-methylenedioxyphenylpropionic acid (V) and P-3-hydroxy-phenylpropionic acid (VI) :A similar react-Jn has been observed by Ciamician and Silber(Ber., 1890, 23, 11621, who have shown that kosafrole (VII), whenreduced by sodium and alcohol, is converted into a mixture of3 : 4-methylenedioxypropylbenzene (VIII) and m-propylphenol(IX), whilst Thorns ( B e y ., 1903, 36, 3449) records the fact thatisomyristicin (X), under similar conditions, yields both 5-methoxy-3 : 4-methylenedioxypropylbenzene (XI) and 5-methoxy-3-propyl-phenol (XII) :O/\CH:CHM~ --3 CH2< I O/\CH,*CH,Me I(VIII. )O\/CH,< I IO\/(VII.)and HO()CH,*CH,M~o/’\cH,~cH,M~O\/I OACH:CHM~ --3 CH,< 1 CH,< I IO\/OMe OMe(XI. 1HO()CH2*CH2Me\/ andOMe(XII.2416 SALWAY: ACTION OF SODIUMIt is worthy of note that in each of the above examples of thedisplacement of a methylenedioxy-complex by a hydroxyl group,the latter appears in the meta-position with regard to the side-chain.Moreover, the position of the unsaturated linking in theside-chain is of importance in determining the course of the reaction,since only those compounds which contain the unsaturated linkingin the aP-position with regard to the benzene nucleus appear tobe capable of undergoing the above-described transformation. Thus,for example, the methylenedioxy-group of isomyristicin (X) is readilydecomposed by means of sodiam and alcohol, whilst myristicin, inwhich the unsaturated linking is in the By-position, does not sufferthis change.EXPERIMENTAL.Reduction of 3-Met7hoxy-4 : 5-m~ethylened~oxycinlzamic ,4 cid(I, p.2415).A solution of one part of 3-methoxy-4 : 5-methylenedioxycinnamicacid in 20 parts of 1 per cent. aqueous sodium hydroxide wasreduced by the gradual addition, with constant stirring, of 16 partsof sodium amalgam (4 per cent.). After the amalgam had beencompletely decomposed, the mixture was acidified, the precipitatedoil extracteg with ether, and the ethereal solution washed, dried,snd the solvent removed. I n this manner the product of reductionwas obtained as a light brown oil, which gradually became crys-talline. A preliminary examination of the product indicated thepresence of a considerable proportion of a phenolic carboxylic acidin addition to the normal reduction product, B-3-methoxy-4 : 5-methylenedioxyphenylpropionic acid.I n order to effect aseparation of these compounds, the mixtnre was dissolved in alcoholand esterified by means of dry hydrogen chloride, after which theexcess of alcohol was removed and the esters extracted with ether.The ethereal solution was first washed with aqueous sodiumcarbonate to remove any unesterified acid, and then shaken withdilute sodium hydroxide. The sodium hydroxide extract, whichcontained the phenolic ester, was warmed for a short time tocomplete the hydrolysis of the latter, then acidified and extractedwith ether. This ethereal extract yielded a colourless solid, whichwas recryst.allised from hot water, when it separated in fiat,hexagonal plates, melting at 1 2 7 O :0.1103 gave 0.2482 CO, and 0.0635 H,O.0.2800 required for neutralisation 14.35 C.C.N / 10-KOH.C = 61.4 ; H = 6.4.M.W. = 195.C,,HI2O4 requires C = 61.2 ; H = 6.1 per cent. M.W. = 196AMALGAM ON METHYLENE ETHERS. 2417As already explained in the introduction, this substance was foundto be B-5-hydroxy-3-methoxyphenylpropionic acid.(3-5-Hydroxy-3-methoxypl~enylpro~onic acid (111, p. 2415) isreadily soluble in ether, alcohol, or hot water, and crystallises fromthe latter in colourless, hexagonal plates, which gradually becomepink on exposure to air. It is insoluble in benzene or lightpetroleum. Its amide, MeO*G,H,(OH)*C'H,*CHz*CO*NH2, crys-tallises from water in prismatic needles, melting at 126O.I n order to prepare the methyl derivative of the above compound,10 grams of the phenolic acid were dissolved in methyl alcohol and5 C.C.of methyl sulphate, and 10 C.C. of a 50 per cent. solution ofpotassium hydroxide added. After the vigorous reaction hadsubsided, the same quantities of methyl sulphate and alkali wereagain added, and the mixture heated for a short time on the water-bath. The alkaline liquid was then acidified and extracted withether, when the ethereal extract yielded an oil which graduallysolidified. This product was purified by crystallisation from amixture of benzene and light petroleum, from which it separatedin clusters of colourless, silky needles, melting at 61-62O :0.1076 gave 0-2490 CO, and 0.0649 H,O.0.4465 required for neutralisation 21.25 c.c: A'/ 10-NaOH.C=63*1; H=6.7.M.W.=210,C,,H,,04 requires C = 62.9 ; H = 6.7 per cent. M.W. = 210.p-3 ; 5-Dim e t hoxy ph en ylpro pionic acid,C,H,(MeO),*CH2*CHz-C0,H,is readily soluble in the usual organic solvents, excepting lightpetroleum. It yields an amide, which crystallises from a mixtureof benzene and petroleum in colourless needles, melting at 80-81O.The position of the methoxy-groups in the above compound wasascertained by oxidising it quantity of the substance with a, hotalkaline solution of potassium permanganate. A t the end of theoxidation, the liquid was cooled, an excess of sulphur dioxide added,and the precipitated oxidation product collected. It was re-crystallised from hot water, when it separated in thin needles,melting at 180-181O.(0.2045 required for neutralisation 11.25C.C. N/10-NaOH. M.W. = 182. Calc., M.W. = 182.)This substance possessed all the properties of 3: 5-dimethoxy-benzoic acid (Bulow and Riess, Ber., 1902, 35, 3901), and wasevidently identical with that compound.Reduction of Piperonylacrylic Acid.The reduction of piperonylacrylic acid by means of sodiumamalgam was first described by Lorenz (Ber., 1880, 13, 758), whoisoIated piperanylpropionic acid from the product of the reaction2418 CAMPBELL AND THORPE : AN IKSTANCE ILLUSTRATINGbut did not record the formation of a phenolic compound. Inview, however, of the results obtained in the above reduction of3-methoxy-4 : 5-met5h-ylenedioxycinnamic acid, it seemed probablethat some P-5-hydroxyphenylpropionic acid would be formed in thoreduction of piperonylacrylic acid.I n order to ascertain if thiswere the case, 20 grams of piperonylacrylic acid were reduced withsodium amalgam in the manner described in connexion with thereduction of 3-methouy-4 : 5-methylenedioxycinnamic acid. Theproduct was then esterified, and, by means of dilute sodiumhydroxide, separated into a non-phenolic and a phenolic ester. Theformer amounted to 18 to 19 grams, and yielded on hydrolysispiperonylpropionic acid, melting at 8 5 O , whilst the latter, whenhydrolysed, yielded a brown oil (2 grams), which gradually solidifiedon agitation with benzene. This substance was purified by re-crystallisation from a mixture of ether and benzene, and was thusobtained in colourless needles, melting at 1 1 0 O . (0.1922 required11.8 C.C. X/lO-NaOH for neutralisation. M.W. = 163. Calc.,M.W. = 166.)This compound possessed all the properties of 3-hydroxyphenyl-propionic acid, and was evidently identical with it (Braunstein,Ber., 1882, 15, 2050).The action of sodium amalgam on piperonylacrylic acid istherefore analogous to that which takes place when 3-methoxy-4 : 5-methylenedioxycinnamic acid is reduced. The yield of phenolicacid in the latter case is, however, much greater than in the former.THE WELLCOME CHEMICAL RESEARCH LABORATOKIES,LONDON, E.C

ISSN:0368-1645    

DOI:10.1039/CT9109702413

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2418 CAMPBELL AND THORPE : AN IKSTANCE ILLUSTRATINGCCXLVII1,- An Instance Illustrating the Stability ofthe Four- Cwbon Ring.By ARTHUR FRED CAMPBELL and .JOCELYN FIELD THORPE.IT has been shown by Bone and Perkin (Trans., 1895, 67, 108)that when a derivative of cyclopropane which has two carbethoxy-groups at,tached to the same carbon atom is treated with the sodiumcompound of et.hyl malonate, condensation ensues, with theformation of an open-chain ethyl ester in t,he following way:?*'>C(CO,Et), -t- CHNa(CO,Et), -+(CO,Et),CNab CH,aCH,*CH(CO,Et),OHTHE STABILITY OF THE POUR-CARBON RING. 2419This reaction has been made use of by us for the preparation ofcertain open-chain nitriles (Trans., 1909, 95, 697 ; this vol., lOOZ),which we found possessed the property of readily passing intoimino-derivatives of cy clopentane when treated with sodiumethoxide, thus :YH2>C(CN)*CO,Et + CHNa(CN)*CO,Et -+ CH, 1 CO,E t *CNa( CN)*CH,*CH,*CH( CN)*CO,E t -+cH2-CH(CN)>C:NH + CO(OEt), +- etc.b H 2 = CH( C0,E t)Wishing to prepare the open-chain compound containing onemore methylene group, in order to study the conditions underwhich it passed into a derivative of cyclohexane, we decided toapply the above reaction to ethyl 1-cyanocyctobutane-1-carboxylate,in the hope that the following react,ion would ensue:CH2<E2>C(CN)*CO,Et + CHNa(CN)-C0,Et -3CO,Et*CNa(CN)*CH,-CH,*CH,*CH(CN)*CO,Et -+~H~<CH,=CH(CO,E~) C H 2 - C H ( C N ) > ~ : ~ ~ + CO(OE~), + etc.,and that in this way an iminederivative of cyclohexane would beformed.We found that this condensation yielded considerablequantities of a crystalline substance melting at 1 1l0, which possessedthe molecular formula CI3Hl8O4N2, that is to say, it seemed to bethe normal open-chain compound of the formula:C02E t. CH( QN) *CE2-C'H,*CH,*CH (C N) *CO,E t.All attempt,s, however, to induce it to react with sodium ethoxideproved unavailing, and we consequently decided that the imino-derivatives of the six-membered ring could not be produced in thesame manner as those of cyclopentane.Before recording this fact, we subjected the open-chain compoundt~ complete hydrolysis in order to prove its constitution by theformation of pimelic acid, when it was found that instead of thisacid the product consisted of cyclobutane-1 : 1-dicarboxylic acid andmalonic acid.Subsequent' experiments showed conclusively that thecondensation product of the formula C,3H,804N2 was ethyl B-imino-a-cyano-1-carbethoxy-P-cyclobutyl-1-propionate (I), and that it hadbeen formed in the following manner :CH,<gB>C(CN)*CO,Et + CH,(CN)*CO,Et -+2CH2<~~2>C(C0,Et)*C( :NH) CH( CN)aCO,Et,(I* 2420 CAMPBELL AND THORPE : AN INSTANCE ILLUSTRATINGThe hydrolysis had evidently therefore taken place in accordancewith the equation:C-tr,<EZ:>C( CO,Et)*C(:NH)*CH (CN)*CO,Et --+CH2<:2>C(CO2H), 2 + CH,(CO,H), + etc,The constitution of the imino-compound was further shown bythe products formed from it on partial hydrolysis. Thus, withdilute alkali hydroxide, it yields the alkali salt of ethyl P-imino-a-cyano-1-curb oxy-P-cyclobut yl-1-popionut e , from which the freeethyl hydrogen salt (11) can be prepared by the action of acids.Thissubstance exists in two well-defined modifications, which melt at75O and 156O respectively. We have named these compounds thea- and &forms of the ethyl hydrogen salt, as we have been unable todetermine their structural relationship :CH2<g2>C( CO,H)*C( :NH) *CH(CN)* C0,Et.(11.1CH,<~~~>CH*C(:NH)~CH(CN)*CO~E~. 2(111.)CH2<E2>CH*C(OK) :C(CN) .COEt.(IV. 1Both modifications lose carbon dioxide when heated, and passinto e thy l fl-imino-a-cyano-P-cyclo b u t y lpropiona t e (111) , a taut o-meric amino-iminecompound, which, when treated with potassiumhydroxide, passes into the stable potassium salt (IV).When asolution of this potassium salt is acidified, ethyl a-cyano-P-cyclo-butylformylacetate (V) is precipitated, and from this compoundcyclobutanecarboxylic acid and malonic acid can be prepared byhydrolysis :2CH2<CHz>CH*CO*CH(CN)* CO,E t --+(V.)CH2CH,<E2>CH*C02H + CH2(C0,H), + etc,The experiments recorded are of interest as showing the relativestability of the cyclopropane and cyclobutane rings under preciselysimilar conditions. The subject has been fully discussed by Perkinand Simonsen in two recent papers (Trans., 1907, 91, 816; 1909,95, 1166), and as our knowledge of these compounds increases, itbecomes evident that any generalisation respecting the stabilit2421 THE STARILlTT OF THE FOUR-CARBON RIKU.and ease of formation of the alicyclic systems must take intoaccount not merely the formation of the rings as such, but alsothe influence exerted by the groups substituting the carbon atomscomposing the rings.We have at the present time a series ofexperiments in progress which it is hoped will throw further lighton this question.E X PER I ME N TB L.Ethyl 1-Cyanocyclobutane-1-carbozylat e,CH,<' H2>C(CN)*C0,Et.CH2This substance was originally prepared by Carpenter and Perkinby the action of bromocyclobutane on the sodium" compound ofethyl cyanoacetate (Trans., 1899, 75, 930). The compound pre-pared by them gave, however, figures on analysis (C=58.59;H = 7-04.C,H,,02N requires C = 62.7 ; €I = 7.2 per cent.). whichclearly showed, as they remarked, that it must have contained nearly50 per cent. of ethyl cyanoacetate. We have prepared a quantityof this mixture in the manner described by Carpenter and Perkin,and find that it is quite impossible, even by repeated fractionation,to separate the cyclic ester from ethyl cyanoacetate, which alwaysaccompanies it. Recently (this vol., p. l002), we had occasion toprepare pure ethyl 1-cyanocyclopropane-1-carboxylate, and foundthat it could be separated from ethyl cyanoacetate by adding thecalculated quantity of sodium ethoxide to the mixture to formthe sodium derivative of ethyl cyanoacetate, and then by addingwater t.o h r m the soluble sodium salt of cyanoacetic acid, leavingthe pure cyclic ester undissolved.We have now applied this method successfully for the preparationof pure ethyl 1-cyanocyclobutane-1-carboxylate in the followingway.The mixed esters prepared by Carpenter and Perkin's methodwere fractionally distilled, and the fraction boiling at 214O wasanalysed. (Found, C =59*21. C8H,,OzN requires C = 62.7.C,H;02N requires C = 53.1 per cent..) The mixture therefore con-tained approximately 37 per cent. of ethyl cyanoacetate. Onehundred grams were therefore added to a well-cooled solution of7.6 grams of sodium in 100 grams of alcohol, and the product wasdiluted with water. The oil which then separated was extracted byether, and the residue left after evaporating the dried etherealsolution was distilled.Pure cthyl 1-cyanocyclobutane-1-carboxylateis a clear, colourless liquid, boiling at 218O/762 mm.:0.2119 gave 0.4856. CO, and 0.1392 H20. C=62*51; H =7*3.C8HI1OgN requires C = 62.7 ; H = 7.2 per cent.VOL. XCVII. 7 2422 CAMPBELL AND THORPE : AN lNSTANCE ILLUSTRATINGEthyl b-Zmino-a-cyano-l-car b e t hoxy-b-cyclobutyl-1-propionu t e,CH2<'*2>C( CO,Et)* C(: NH) *C H(CN)*C02Et.CH2This substance was prepared by the condensation of ethyl sodio-cyanoacetate with ethyl 1-cyanocyclobutane-1-carboxylate in thefollowing manner. 2.3 Grams of sodium were dissolved in 30 gramsof alcohol, and the solution, after being mixed with 11.3 gramsof ethyl cyanoacetate, was treated with 15.3 grams of ethyl 1-cyano-cyclobutane-1-carboxylate, and the whole heated on the water-bathfor three hours. A t the end of this time the dark-coloured,gelatinous product was mixed with water, and after the solutionhad been rendered faintly acid by acetic acid, it was distilled in acurrent of steam until the distillate was free from oil. The non-volatile residue, which solidified on cooling, was collected andcrystallised from alcohol, from which solvent it separated in small,rectangular plates, melting at 11 lo :0.1861 gave 0*4007 CO, and 0.1151 H,O.0.2012If the mixture of ethyl 1-cyanocyclobutane-1-carboxylate andethyl cyanoacetate is used in this experiment instead of the purecyclic ester, the product always consists of the above cyclic imino-compound mixed with ethyl B-imino-a-c yanoglut ar at e,C02Et *CH2-C (:NH) *CH( CN) *CO,E t,which has been formed by the condensation of ethyl cyanoacetatewith its sodium derivative. The mixture may be separated bymeans of boiling sodium carbonate solution, which hydrolyses ethylP-imino-a-cyanoglutarate t o the sodium salt of ethyl hydrogen8-imino-a-cyanoglutarate, and leaves the cyclic imino-compoundiinc hanged.C = 58.7 ; H = 6.87.N=10*7.= 10.5 per cent.,, 18.0 C.C.N, at 9 O and 757 mm.C,,H,80aN2 requires C = 58.6 ; H = 6.8 ;The a- an,d j3-forms of Ethyl j3-Zmino-a-cgano-l-carboxy-~-cyclobzctyt -1-propionate, CH2<CH2>CH( CO,H)*C(: NH) *CH( ON)* C02Et.CJ32The two forms of this ethyl hydrogen salt are produced by theaction of potassium hydroxide on ethyl B-imino-a-cyano-1-carbethoxy-B-cyclobutyl-1-propionate, the a-f orm at low temperatures, theB-form when the reaction is carried out at the temperataure ofboiling water.The conditions found most suitable for theirproduction were as follows.a-Form. - Ethyl 8-imincm-cyano-1-carbet hoxy-P-cy cZobutyI-1-pro-pionate slowly dissolves when shaken with a solution containingrather more than the calculated quantity of potassium hydroxidTHE STABILITY OF THE FOUR-CARBON RING. 2423dissolved in three times its weight of water, and if, when all haspassed into solution, hydrochloric acid is cautiously added untilan acid reaction is obtained, an oil separates which solidifies onbeing scratched. When crystallised from warm water, this form ofthe ethyl hydrogen salt.is obtained in colourless needles, which meltat 75O, and lose carbon dioxide at a higher temperature:0.1798 gave 0.3633 CO, and 0.0927 H,O.C,,H,,O,N, requires C = 55.4 ; H = 5.8 per cent.The a-form is very unstable, and readily gives off carbon dioxide;even when an aqueous solution of it is boiled, considerable decom-pmition ensues.B-Form.--Some of this modification always accompanies thea-form, and can be obtained from the mother liquors employed inits recrystallisation. It can be prepared as chief product by usingthe following conditions. Ethyl P-imino-a-cyano-1-carbethoxy-B-cyclobutyl-1-propionate is suspended in boiling water, and rathermore than the calculated quantity of aqueous potassium hydroxideadded to the hot liquid. The ester quickly dissolves, and thesolution is then cooled and acidified, when crystals separate at once.When recrystallised from hot water, the small prisms of the P-formare obtained, which melt and evolve carbon dioxide a t 15G0:C=55*1; H = 5.72.0.1790 gave 0.3649 CO, and 0.0937 H;O.Cl,H,,04N2 requires C: = 55.4 ; H = 5.8 per cent.The &form of the ethyl hydrogen salt is very stable, and can beboiled with water for a considerable time without undergoingchange. The alkali salt of the a-form is completely transformedinto the alkali salt of the &modification when its aqueous solutionis boiled, but the reverse change could not be effected.C = 55.6 ; H= 5.8.Ethyl p-ir,ino-a-cyano-fl-cyclobutylpropionate,This substance is formed when either the a- or P-form of ethylB-imincla-cyano-l-carboxy-B-cyclobutyl-l-propionate is heated untilthe evolution of gas has ceased.The operation is conducted in atest-tube heated in a bath of sulphuric acid, and when all carbondioxide has been evolved, the residue, which solidifies on cooling,is crystallised from dilute methyl alcohol. The imino-compoundforms slender needles, which melt at 105O:0.1821 gave 0.4125 C'O, and Om12O3 H,O.C,,H,,O,N, requires C = 61.9 ; H = 7.2 per cent.Ethyl B-imino-a-qano-B-cyclobut ylpqp*onnte is a tautomerichino.amino(ketimino-enamic)-derivative, which is slowly hydrolysedC = 61-78 ; H = 7-34.7 1 . 2424 CAMPBELL AND THORPE : AN INSTANCE ILLUSTRATINGby dilute mineral acid to the corresponding ketone. It is also readilyhydrolysed by aqueous alkali hydroxides, forming the stable alkalisalt of the enolic form of the ketone.Ethyl a-Cyano-b-cyclobut ylfomn ylacetat e,CH2<Z2>CH*CO*CH( ON) * C0,Et.This substance can be prepared by the action of dilute sulphuricacid on the last-named imino-compound, but is more convenientlyproduced by the action of aqueous potassium hydroxide.Fivegrams of the imino-compound are mixed with water, and slightlymore than the caIcuIated quantity of aqueous potassium hydroxideis added. The imino-compound rapidly dissolves when the solutionis warmed, ammonia being evolved at the same time, and if, whenall has passed into solution, it is rendered acid by hydrochloricacid, an oil is precipitated which can be extracted by ether.It isadvisable, in order further to purify the ketone, to shake theethereal solution with aqueous sodium carbonate, and then torecover the ketone by acidifying the alkaline extract and extractingit again with ether. Ethyl a-cyano-/3-cyclobutylformylacetate is acolourless oil, which boils at 18Z0/25 mm. :0.2077 gave 0.4676 CO, and 0-1270 H,O.The ester dissolves readily in aqueous alkali hydroxides and insolutions of alkaline carbonates. It gives an intense red colorationin alcoholic solution with ferric chloride.The silver salt separates as a microcrystalline precipitate whenthe calculated quantity of silver nitrate solution is added to aneutral solution of the ammonium salt of the ketone:C = 61.41 ; H = 6.8.C,,H,,O,N requires C = 61.5 ; H = 6.7 per cent.0.2973 gave 0.1062 Ag.Ag=35*72.The salt rapidly becomes coloured on exposure to light,C,,H,,O,NAg requires Ag = 35.76 per cent.Formtion of cycloButane-1: l-dicarboxylic Acid and Malortic Acidf ?.om Ethyl /3-lmino-a-cyano-l-car b e t hoxy-fl-c y clo b u t y 1-1 -prop'ona t e.This decomposition was effected by boiling 7 gra.ms of the imino-compound with 20 per cent. sulphuric acid for four hours; theresulting clear solution was then distilled in a current of steamuntil the odour of cyclobutanecarboxylic acid, which resembles thatof isobutyric acid, ceased to be apparent, and the distillate showeda neutral reaction. The non-volatile residue was then saturatedwith ammonium sulphate, and extracted repeatedly with ether.The dried ethereal extract, on evaporation, left a residue whicTHE STABILITY OF THE FOUR-CARBON RlNG.2425solidified. This was found to consist of a mixture of cyclobutane-1: 1-dicarboxylic acid and malonic acid, and was separated bytreatment with concentrated hydrochloric acid, in which the cyclicacid is insoluble. The pure acid was obtained in prisms, meltingand decomposing at 155O. (Found, C = 49.98 ; H =5#73. Calc.,C = 50.0 ; R = 5.5 per cent.)Malonic acid was recovered from the mother liquors used in theseparation of the a.bove acid by evaporating them to dryness andextracting the residue with ether. It was characterised by itsconversion into acetic acid on distillation.Formation of cycloRutan~ecarbozylic Acid and Malonic Acid fromEthyl a-Cyano-B-cyclo bictylformylacetat e.Some cycZobutanecarboxylic acid is formed in the hydrolysis justdescribed, and can be recovered from the steam distillate. Thequantity is, however, very small, being only about 3 per cent. ofthe amount of imino-compound hydrolysed. The cyclic acid can,however, be prepared in quantitative yield from ethyl a-cyano-/3-cycZobutylformylacetate in the following manner. Ten grams areboiled with 20 Eer cent. sulphuric acid for four hours, when theacid solution is distilled in a current of steam until the distillateceases to be acid. The distillatme is then saturated with ammoniumsulphate and extracted with ether. The dried ethereal extractleaves a residue on evaporation which distils at. 19l0, and possessesa characteristic odour resembling that of isobutyric acid. The acidwas converted into its silver salt, which crystallises from hot waterin long needles. (Found, Ag = 52.3.The non-volatile portion from the steam distillate was saturatedwith ammonium sulphate and extracted with ether. The residue,on evaporating the ether, melted at 13Z0, and was proved t o bemalonic acid by converting it' into acetic acid by distillation.Calc., Ag = 52.2 per cent.)THE Sonny RESRARCII LABORATORY,THE UNIVERSITY,SH EFFI ELD

ISSN:0368-1645    

DOI:10.1039/CT9109702418

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2426 LAMBERT AND TNOMSON :CCXL1X.-The Wet Oxidation of Metals. Part I.The Rusting of I r o n .By BERTRAM LAMBERT (Goldsmiths’ Research Student) andJAMES CAMPBELL THOMSON.THE work of Moody (Trans., 1906, 89, 720) and Friend (Proc.,1910, 26, 179) would seem to point+ to the fact that ordinary‘(commercial” iron can, in some circumstances, be kept for aconsiderable time without undergoing visible oxidation in contactwith water and air freed from acid gases, such as carbon dioxide.These experiments are perhaps generally accepted as strongevidence in support of an explanation of the rusting of iron whichwas originally put forward by Crum Brown in 1888. His theoryis that the rusting of iron is due primarily to the interactionbetween iron, carbon dioxide, and water, with the formation offerrous bicarbonate, which then reacts with oxygen to form ferricoxide.The impurities contained in the best commercial iron must, fromit chemical point of view, be regarded as considerable, and, in thelight of our present knowledge of the great modifications capableof being produced in the properties of substances by the presenceof even minute traces of impurities, it cannot be contended thatexperiments with impure iron afford trustworthy grounds for a,satisfactory theory of the oxidation of iron.The aim of the present investigation was to bring together, underthe simplest possible conditions, the purest obtainable water,oxygen, and iron, in vessels which would be least likely to be actedon by any of these substances.The results have been to show that chemically pure iron willnot undergo visible oxidation even after long exposure to purewater and pure oxygen in vessels made of clear fused silica.Further, that a very small trace of impurity in the iron is sufficientto cause oxidation under exactly the same conditions, where thereis not the remotest chance of any acid substance either beingpresent or being formed during the reaction.Description of Apparatus : Preparation of Oxygen und Water.Oxygen.-The oxygen used in the experiments was prepared bythe electrolysis of a solution of barium hydroxide in “ conductivity ”water.The barium hydroxide was purified by recrystallisingtwelve times. The solution wm electrolysed between platinuTHE WET OXLDATION OF METALS.PART I. 2427plates in a cell A (Fig. l), the air entering the reservoir of the cell,owing to changes of pressure during the electrolysis, being purifiedby passing through tubes containing sulphuric acid and soda-lime,as shown a t 23. The oxygen was stored in a series of flasks, D, ofabout 2 litres capacity. Before reaching the storage vessels, theoxygen was passed through a U-tube containing lumps of puresodium hydroxide to remove the excess of aqueous vapour. Thiswas found necessary in order to protect the lubrication of phosphoricacid on the tap E, which connected the oxygen storage with therest of the apparatus. Even with this precaution, it was foundthat there was a slight leakage round this tap when there was ahigh vacuum in the rest of the apparatus.This was prevented byFIG. 1.introducing a, mercury trap of the hype shown in the figure ab F.(The principle of this trap is explained later.)All the taps were mercury-sealed and lubricated with glacialphosphoric acid.I.Vater.-The water was prepared by distillation, in a vacuum,from a concentrated solution of barium hydroxide. The bariumhydroxide, purified as before, was dissolved in ‘‘ conductivity ”water in the flask P, which waa separated from the rest of theapparatus by a thin bulb, N , sealed into a wider tube connectingwith the rest of the apparatus, as shown in the figure. Connexionwas made between the water supply and the rest of the apparatus,at the proper time, by causing the glass rod at ill to drop on thethin bulb N and break it,.The air in contact with the baryta solution was removed throughthe sidetube 0, which was drawn out to a capillary and attachedto a good water-pump.The water in the flask was then boiledvigorously, under diminished pressure, for two or three hours, th2428 LAMBERT A N D TIIOMSON :capillary being sealed while the water was boiling. I n this wayall but the smallest traces of air were removed from the flask.The “ conductivity ” water used to prepare the solutions ofbarium hydroxide for the cell A and the flask I> was made byI<ohlrausch’s method by distillation through alkaline and acidsolutions of potassium permanganate. It was condensed in a block-tin condenser, and collected and stored in a large Jena-glass flask,with arrangements for syphoning off and for protecting it fromcontact with impure air, as used by Hartley, Campbell, and Poole(Trans., 1908, 93, 428).Only the middle portions of the distillatewere used. This water was also used in the final washing of allparts of the apparatus before they were set up.The choice of the kind of vessel in which to carry out theexperiments was the cause of much difficulty. It was finally decidedto use vessels made of transparent fused silica as being least likelyto be affected by either water, iron, or oxygen. After many trialsand experiments, a simple form of glass vessel was devised, which,with a tube of dear fused% silica, gave all the advantages of anapparatus made entirely of silica, Eince the water which collectedin the silica tube and cama in contact with the iron must havecondensed on the inside of the silica tube itself.The silica tubeswere about 8 cm. in length and 1 cm. in diameter, and were closedat one end.A silica tube was made to slide loosely into an outer glass vessel,of the shape shown at V in the figure, and to be so supported bythe lower end of the glass vessel that the open end of the tubeand half its length were not in contact with the glass. The pureiron (preparation described later) was put into the silica tube,which was then placed in the outer glass vessel; the glass vesselwas then closed at the top and sealed into position by means of thesite-tubes connecting with the oxygen sup-ply and the water supply,as shown in the figure.These side-tubes were drawn out tocapillaries in order to facilitate the sealing off of the vessel whenthe experiment was finished. (Three o r four such vessels were usedin each experiment, and were sealed on in parallel.)Between the vessel V and the water supply was a trap L, to catchand retain any water which condensed before reaching this point.Between the vessel V and the oxygen supply was a trap K , of shapeshown in the figure, the use of which is explained below, and atube H , containkg glass-beads covered with pure gold-leaf. Thisdevice was used t o protect the vessel containing the iron from con-tamination with mercury vapour, for, in evacuating the apparatus,a very high vacuum was obtained, and mercury was contained bothin the trap F and in the pumps.THE WET OXIDATION OF METALS.PART I. 2429All joints in the apparatus were sealed glass joints, and no rubberconnexions of any kind were used.All the glass parts of the apparatus were very thoroughly cleanedand steamed, at intervals, for several hours.The silica tubes were boiled with pure concentrated nitric acidfor several weeks, and were afterwards steamed and boiled withconstant changes of freshly made conductivity water for severaldays, They were finally heated strongly in a, clear blow-pipe flame.The whole apparatus was connected, beyond the tap X, with acombined Sprengel and Topler pump and a drying tube containingphosphoric oxide.Method of Conducting the Experiment.-The whole apparatusbetween the bulb N (separating the water supply) and the tap Cwas evacuated.The tap E was then closed, and the storage vesselsD filled with oxygen made by electrolysis of the baryta in the cell A .The capillary a t G was sealed, so that any slight leakage of oxygenround the tap E merely served to push up the mercury in thetrap F, and did not affect the vacuum in the rest of the apparatus.The thin bulb N was then broken by causing the heavy glass rod Mto fall on it. It wax usually found that there was a little residualair in the flask P, which had not been completely removed in theboiling off process. The quantity of air was extremely small, andwas easily removed by working the mercury pumps for a fewminutes.The flask P was then very gently heated on a water-bath, thetemperature never being raised so high as to promote rapidevaporation.The first portions of water were caused to condensein the vessel Ii by surrounding it with ice. When the watercollected in K reached a depth of about 12 cm., the lower end ofthe vessel T’ was cooled, and wa.ter slowly condensed inside the silicatube and in contact with the iron. The wa>ter collecting in thesilica tube must necessarily have condensed only on silica; a.nywater which condensed on the glass vessel supporting the silica tubesimply running down and collecting outside the silica tube.When a sufficient quantity of water had been obtained in contactwith the iron, the capillary to the right of Y was sealed off bymeans of a small flame.Oxygen was then allowed to enter theapparatus by slowly opening the tap Z. This pure oxygen, beforeentering V , was washed by passing through the pure water collectedin the trap K for this purpose. ?‘he capillary to the left of V wasthen sealed, thus leaving the iron in contact with pure water andpure oxygen in a sealed vessel. The vessel was put aside forobservation.Preparation of Pure Iron.-The material employed in the pre2430 LAMRERT AND THOMSON :paration of pure iron was a pure specimen of Kahlbaum ” ferricchloride. The salt was found to be free from sulphate, arsenic,alkali, or alkaline earth metals. A solution of the salt was madein conductivity water and electrolysed between elect’rodes of pureiridium foil. This method is made possible by the fact that pureiridium is not attacked by chlorine, which is evolved at the anode.The metallic iron which was deposited on the cathode was thenthoroughly washed with conductivity water, and dissolved in puredilute nitric acid.This solution of ferric nitrate in excess of nitricacid was concentrated on the water-bath, and the salt crystallisedfrom the solution in concentrated nitric acid. The crystal! wereseparated from the mother liquor, washed with pure concentratednitric acid, and recrystallised four or five times from this solvent.The crystals so obtained were colourless, or white when seen in bulk.It is to be noticed that ferric nitrate, prepared from ordinary pureFIG. 2.iron, has, when seen in bulk, a pale violet colour like that of ironalum, and that the colour cannot be removed by repeated crys-tallisation from pure nitric acid.The ferric nitrate crystals were transferred by means of a spatulaof iridium foil to a pure iridium boat. The boat was then heatedin air on a thick tile, so that the flame gases did not come incontact with it.The ferric nitrate was thus converted into theoxide or basic nitrate. The boat containing the flakes of oxide wasthen placed into a transparent silica tube, and heated in an electricresistance furnace to a bright red heat (just above 1000°), while astream of pure hydrogen wits passed through the tube.* Fig. 2* In some experiments the oxide was heated in a stream of pure oxygen for severalhours before being reduced, in order to remove the occluded nitrogen which iscontained in most oxides formed from nitrates.This operation, however, wasfound to be unnecessary, since the properties of the resulting iron were exactly thesame as when the oxide or basic nitrate was directly reduced in hydrogen. ThTHE WET OXtDATION OF METALS. PART I. 2431shows the arrangement of the apparatus for this operation. Thehydrogen was prepared by the electrolysis of a solution of purebarium hydroxide. The figure only shows half the electrolytic cell,which contains two pairs of large platinum electrodes and is capableof producing a steady stream of hydrogen. The gas was passedthrough a U-tube containing lumps of pure sodium hydroxide, inorder to remove excess of water vapour, and then through anotherU -tube containing tightly-packed glass wool.The metallic iron so obtained, by direct reduction of the flakesof oxide or basic nitrate, had a distinct metallic lustre and a lightgrey colour.I f the flakes of oxide were ground in an agate mortarbefore being reduced, the iron produced by reduction was lightgrey in colour, but had little or no lustre. The properties of thetwo kinds of iron were the same.The Jena-glass beakers used in the preparation of the ferricnitrate were thoroughly cleaned and boiled out for several weekswith constant changes of pure concentrated nitric acid. They werealso steamed out at intervals for several hours. The sametreatment was applied to a G m h crucible, which was used forseparating and washing the ferric nitrate crystals.The iridiumboat was boiled for several weeks with aqua regia and then withconcentrated nitric acid; it was finally heated to a high temperaturein a stream of hydrogen in the electric resistance furnace.The nitric acid used throughout in the preparation of ferricnitrate was made by the distillation, under diminished pressure,of a pure commercial nitric acid. The acid was distilled twice, thefirst and last portions of the distillate being discarded in both cases,Fig. 3 shows the apparatus which was used for the distillationof the nitric acid. The acid was introduced into the distilling flaskA by means of the side-tube B, which was then sealed off. Theconnexions between distilling flask9 condenser, and receiver weresealed joints.Nitric acid distilled under low pressure is very liableto froth violently, and SO a large trap was introduced at C. A goodwater-pump was used to evacuate the apparatus through the tap D.The acid was drawn off through the tube E by cutting off a smallportion of the capillary, which was sealed up again immediatelyafterwards. After this apparatus had been used for several weeksand the surface alkali had been dissolved from the glass, the nitricacid obtained was very pure, and 50 C.C. left no weighable residuewhen evaporated to dryness on the water-bath. The productslight surface oxidation undergone by the iridium did not seem to affect the iron.The occluded nitrogen was undoubtedly removed by heating in hydrogen to thehigh temperature of the furnace.This temperature was between the melting pointof silver and that of copper2432 THE WET OXIDATION OF METALS. PART I.obtained by distilling nitric acid from a platinum retort was notnearly so good,It is to be noticed that throughout the preparation of pure ironthe use of platinum apparatus was avoided.Results of Experiment and Conclusions.It was found that pure iron, prepared exactly as described above,did not undergo any visible oxidation when treated with pure waterand pure oxygen in vessels made of clear fused silica, and that therewas no change even after several months.I f , however, ferric nitrate, prepared from ordinary pure iron,was used, even after ten recrystallisations, and iron made from itFIG.3.by precisely the same method, the iron invariably showed signs ofoxidation in two or three hours, and, after twelve hours, therewas always a considerable deposit of reddish-yellow ferric oxide onparts of the metal. Oxidation also took place even when the oxideprepared from the nitrate was strongly heated in a stream of pureoxygen for several hours before being reduced to the metal.It is impossible that iron prepared in this way can containanything more than a very slight trace of impurity, and thatimpurity, whatever i t may be, cannot be of such a nature that itis acid, or will give an acid on oxidation.Again, if platinum vessels were used, particularly if a platinumboat was used in which to reduce the iron, the iron produced readilyunderwent oxidation in two or three hours, and oxidation invariablytook place at those parts of the metal which had been heated incontact with the platinum boatPREPARATION OF SECONDARY AMINES.2433Richards (PTOC. Amer. Acnd., 1900, 35, 253>, in his work on theatomic weight of iron, prepared iron in somewhat the same way aswe have done, but he distilled the nitric acid used from a platinumretort, and employed platinum vessels throughout for his pre-paration. He states that the iron always contained slight tracesof platinum, and thatl, when it was dissolved in acids, a small blackspeck of platinum remained.This small trace of platinum, which may be mereIy attached tothe iron, o r may be present in the form of a solid solution, wouldseem to be enough to cause oxidation to take place.All kinds of commercial iron which were used readily rustedunder the same conditions of experiment, as also did iron madewith the most scrupulous care by many other methods.A specimen of commercial electrolytic sheet iron (99.9 per cent. ofiron), which had been polished and treated with a 1 per cent.solution of chromic acid for three months, and afterwards washedwith pure water and quickly dried, readily rusted under the sameconditions of experiment. This method of treating ordinary ironis said by Moody to remove the impurities from the surface of theiron. It seems probable that other reasons must be sought forthe non-rusting of the commercial iron used by Moody under hisprecise conditions of experiment.It would seem to be proved from these experiments that pureiron will not undergo visible oxidation in contact with pure waterand pure oxygen, but that a small trace of impurity in the ironis sufficient to cause oxidation under exactly the same conditionsof experiment, even if this impurity be not of an acid nature orlikely to produce an acid during the reaction.CH FMICAL DEPARTMENT,UNIVERSITY MUSEUbf, OXFORD

ISSN:0368-1645    

DOI:10.1039/CT9109702426

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

PREPARATION OF SECONDARY AMINES. 2433CCL-Pwparation of Secondary Amines from Cuq*b-oxylic Acids. Pa9-t I. P~re~xwatio~~ of Hepta-decylaniline, Pentaclecylaniline, ayhd Fridecyl-aniline.By HENRY RONDEL LE SUEUR.THE method most generally employed for the preparation ofsecondary amines consists in the interaction of an alkyl haloidcompound and a primary amine. A serious objection to this methodis that tertiary amines are also formed, and the subsequen2434 LE SUEGR : PREPARATION OF SECONDARYseparakion of the secondary amines from these is a matter of con-siderable difficulty. Further, this method necessitates the use ofalkyl monohaloid compounds, and these, with the exception of thelower members, are not always easy to prepare.The method which is now brought forward for the preparation ofmonoalkylanilines, and which, so far as can be ascertained, is new,is free from these two objections, as, firstly, owing to the natureof the reaction, there is no possibility of the formation of dialkyl-anilines, and, secondly, the entering alkyl group results directlyfrom an acid, and acids are more easily obt.ained,than any otherclass of organic compounds.The new method is briefly as follows:(1) the a-anilino-acid is prepared by the interaction of aniline andthe a-bromo-acid, ('2) the a-aniIinobacid is heated to considerablyabove its melting point, whereby it loses carbon dioxide, and amonoalkylaniline results :CH,*[CH,],,*CHBr*CO,H + C6H,*NH, =a-Bromostearic acid.CH3-[CH2],,*CH(NHPh}*C02H + HBr.a-Anilinostearic acid.CH3*[CH,],,*CH(NHPh)*C02H Et",d CH,-[CH,],,*CH,*NIIPh + CO,.I n the three caes so far investigated, and which form the subjectof this communication, the yield of a-anilineacid was more than70 per cent.of the theoretical, and the yield of alkylaniline wasalso more than 70 per cent. of that theoretically obtainable fromthe anilino-acid.a-Anilinostearic acid, a-anilinopalmitic acid, and a-anilinomyristicacid have been already prepared by Hell and his collaborators (Rer.,1889, 22,1748; 1891,24, 942,2395), who obtained these compoundsby the interaction of aniline and the respective a-bromo-acid a t180-185O. Heating to 180-185° is not necessary, and is to beavoided, as at this high temperature there is a likelihood of theanilino-acid undergoing decomposition, and also of the formation ofan anilide and of an aS-unsaturated acid, the latter being formedby the removal of hydrogen bromide from the a-bromeacid by theaniline.Heptadecylaniline, C',7H,,*NH*C6H,, pentadecyluniline,C,,H,,*NH-C,H,, and tridecylanilime, Cl3H2,-NH=C,H,, are colour-less solids, which melt at a low temperature, and are readily solublein most of the common organic solvents. Their hydrochlorides areinsoluble in cold water, and when heated with this liquid they meltand undergo almost complete hydrolysis into the free base andhydrogen chloride.The author is now engaged in the investigation of the applicationof the above reaction to the preparation of secondary amines inHeptadecylanilineAMINES FROM CARBOXYLlC ACIDS.PART 1. 2435general, and more particularly of monoalkylnaphthylamines andother monoalkylanilines, and from the results so far obtained it isevident that this method is not limited to the preparation of thehigher monoalkylanilines.EXPERIMENTAL.Preparation of a-Anilinostearic Acid, ClGH,,*CH(NHPh)*CO2H.Thirty grams of a-bromostearic acid (1 mol.) and an equal weightof aniline (4 mols.) were heated together in a flask immersed inboiling water for thirteen hours, The resulting solid was thoroughlydigested with excess of hot dilute hydrochloric acid, collected, andwashed with dilute acid and water to remove excess of aniline; i twas then dried and cryst'allised from a mixture of alcohol and ethylacetate, when 23 grams of the pure acid were obtained.(Found,C = 76.54 ; H = 10.75 ; N = 3-91. Calc., C = 76-80 ; H = 10'93 ;N=3*73 per cent.)a-Anilinodearic acid is sparingly soluble in alcohol, acetone,benzene, or chloroform in the cold, but dissolves readily on heating.It is insoluble in water, ether, or light petroleum, and separatesfrom ethyl acetate in nodular aggregates, melting at 141--142O, andnot at 84*5O, as stated by Hell and Sadomsky (Ber., 1891, 24,2395). The low melting point given by Hell and Sadomsky isobviously not in agreement with the value to be expected fromanalogy to other similar a-anilino-acids.Heptadecylaiziline, Cl7H,,*NH*C6H,.Five grams of a-anilinostearic acid were placed in a small flaskcontaining a thermometer, the bulb of which dipped into the sub-stance, and the whole heated in a metal-bath.As soon as thesubstance was melted, the temperature was raised rapidly to about190°, at which point the evolution of carbon dioxide commenced.The temperature was then raised more slowly to 270-280°, andthe heating stopped when the evolution of carbon dioxide hadceased. The evolution of carbon dioxide is very rapid a t about220°, and there is no evidence of charring or secondary decom-position at any sta,ge of the heating, which for 5 grams of acidrequires about fifteen minutes. %'he product resulting from 20grams of anilineacid, heated in quantities of 5 grams at one timeas described above, was distilled under 50 mm. pressure, when 14-3grams of distillate, boiling between 295O and 300°, were obtained.This was redistilled under 35 mm.pressure, and gave:Below 285" ................................................ 2.3 grams.Undistilled residue = 2-0 grams.285-290" ................................................ 10.0 ,2436 LE SUEUR : PREPARATION OF SECONDARYThe fraction 285--290° readily solidified to a white solid meltingat 4 1 - - - 4 2 O , arid consisted therefore of the pure amine, and, asnearly the whole of the fraction distilled a t 285-286OY this tem-perature is to be regarded as the boiling point of the pure substance.The amine was also purified by crystallisation instead of fractionaldistillation, in which case the method adopted was as follows. T l eproduct resulting from the heating of the anilino-acid was distilledin a vacuum and the distillate dissolved in ether, the etherealsolution washed with a solution of potassium hydroxide, dried withsolid potassium hydroxide, and the residue left on evaporation ofthe ether crystallised from alcohol until its melting point wasconstant.This alternative method of purification is especiallyapplicable to the preparation of small quantities of the amine :0.1632 gave 0.5000 (20, and 0.1836 H,O. C= 83.55 ; H='12.50.0.2380 ,, 8.7 C.C. N, (moist) at 12O and 770 mm, N=4.40.C,,H,,N requires C = 83-38 ; H = 12.38 ; N = 4.23 per cent.Heptadecylmdine is readily soluble in ether, benzene, chloroform,acetone, light petroleum, or ethyl acetate in the cold, sparingly so incold alcohol, but readily so on warming, and crystallises from thissolvent.in large plates, which soon change to long needles, the latterbeing the stable crystalline form. Heptadecylaniline melts at42--43O, and boils at 285-286Oj35 mm. It is insoluble in hydro-chloric acid, but dissolves readily in concentrated sulphuric acid.The hydrochloride, CI7H3,*NH*C,H,,HC1, was obtained by dis-solving 1.5 grams of the amine in 50 c . ~ . of ether, and passing dryhydrogen chloride into the solution until saturated. The pre-cipitated hydrochloride was collected, wa*shed with ether, dried, andcrystallised from light petroleum (b. p. 60-80°), when it wasobtained in beautiful, thin, glistening plates, melting at 99-looo.It is sparingly soluble in alcohol, ether, acetone, benzene, or lightpetroleum in the cold, and readily dissolves in cold chloroform orboiling light petroleum.It is insoluble in cold water; in hot water,however, the substance melts, but does not dissolve, and the aqueousliquid acquires a strongly acid reaction. 0.2856 Gram, suspendedin hot water, required 7.8 C.C. ,V/lO-NaOH for neutralisation of theaqueous solution, using methyl-orange as indicator, whereas the sameweight of the compound, C17H35*NH*CGH5,HC1, requires 7.8 C.C.A'/ 10-NaOH.The acetyl derivative, C,,H3,*N(CH3*CO)*C,H5, was readily pre-pared by boiling together half a gram of the amine and two gramsof acetic anhydride for one and a-half hours. The excess of aceticanhydride was removed by allowing the product to remain in avacuum over a saturated solution of potassium hydroxide, and thAMINES FROM CARBOXYLIC ACIDS.PART I. 2437solid residue was purified by crystallisation from methyl alcoholcontaining a small quantity of water:0.1690 gave 5.9 C.C. N, (moist) at 20° and 750 mm.C,,H,30N requires N = 3.75 per cent.A cetoheptadecylanilide is readily soluble in most of the ordinaryorganic solvents, and crystallises from methyl alcohol containing alittle water in feathery aggregates of slender needles, melt,ing at42-43O.The nitrosoarnine, C17H3j*N(NO)*C6H6, was most easily obtainedby the following method, which gave a practically theoretical yieldof the pure substance. 1-5 Grams of the amine were dissolved in10 C.C. of concentrated sulphuric acid, and this solution added dropby drop to a solution of 3 grams of sodium nitrite in 80 C.C.ofwater, the whole being vigorously shaken, and more (about 2 grams)sodium nitrite added from time to time. The resulting solid wascollected, washed, dried, and crystallised from methyl alcohol :N = 3.94.0.1520 gave 10.5 C.C. N, (moist) at 18.5O and 760 mm.C,,H,,ON, requires N = 7.78 per cent.P~emyl~eptadecyllzitrosoamine is readily soluble in ether, chloro-form, benzene, light petroleum, or acetone in the cold, sparinglyso in cold methyl alcohol, but dissolves readily on heating, andcrystallises from this solvent in light f awn-coloured plates, meltingat 53-54O. A small quantity of the nitrosoarnine, mixed with alittle phenol and warmed with concentrated sulphuric acid, gave ablue solution, which, on dilution, gave a red, opalescent liquid,turning blue on being rendered alkaline.N= 7-96.Preparation of a-Anilinopdmitic Acid.Thirty grams (1 mol.) of a-bromopalmitic acid and an equalweight (3+ mols.) of aniline were heated togejher in a flask immersedin boiling water for seven hours, and the resulting product w5~9worked up as described for the preparation of a-anilinostearic acid(p.2435). The crude acid was purified by crystallisation from itmixture of alcohol and ethyl acetate, and was obtained in nodules,melting at 143--144O, a melting point which agrees with that givenfor this substance by Hell and Jordanoff (Ber., 1891, 24, 942). Theyield of pure acid obtained corresponded with 80 per cent. of thetheoretical.(Found, N = 4.09. Calc., N = 4.03 per cent.)Pemtadecylan&%ze, C,,H3,-NH*C6H,.The a-anilinopalmitic acid was heated in quantities of 5 grams ina flask immersed in a metal-bath, as described for the preparation ofVOL. XCVII, 7 2438 LE SUEUR : PREPARATLON OF SECONDARYheptadecylaniline (p. 2435). The evolution of carbon dioxide com-menced at about 190°, was rapid at 220°, and had ceased afterfifteen minutes' heating, the temperature having risen at the endof that time to 2 8 0 O . The product resulting from 29 grams ofanilino-acid heated as described above was distilled under 40 mm.pressure, when the following fractions were obtained :Below 274" ............ 2.8 grams. 1 290-340" .............. 2-3 grams.The fraction 274-290° was redistilled under 40 mm.pressure,when 16 grams, boiling at 271-27407 were obtained, which solidifiedto a colourless solid, melting at 32-33O, and consisted of the pureamine. The fraction boiling below 274O on crystallisation fromalcohol gave 1.6 grams of the pure substance. The total weight ofpure amine obtained from 29 grams of anilino-acid was 17.6 grams,which corresponds with a 70 per cent. yield of the theoretical:0.1488 gave 0.4548 CO, and 0.1640 H,O.0-2164 ,, 8.8 C.C. N, (moist) at 18O and 762 mm. N=4*71.C21H37N requires C = 83-17 ; H = 12-21 ; N =4.62 per cent.Pentadecylaniline is readily soluble in ether, benzene, chloroform,acetone, light petroleum, or ethyl acetate in the cold, is sparinglysoluble in cold alcohol, but dissolves readily on warming, andcrystallises from this solvent in feathery aggregates, melting at;34-35O.It is insoluble in hydrochloric acid, but dissolves readilyin concentrated sulphuric acid. The pure amine boils at 271°/40 mm.The hgdrochloride, C',,H,,*NH*C,H,,HCl, was readily obtainedby passing dry hydrogen chloride into a solution of 1 gram ofpentadecylaniline in 30 C.C. of ether, when the pure hydrochloridesoon crystallised in glistening plates, which melted at 97'5O. It isinsoluble in ether, acetone, benzene, or light petroleum in the cold,dissolves readily in cold chloroform and in boiling light petroleum,from which it separates in glistening plates on cooling. It isinsoluble in water, and when heated with this solvent it melts butdoes not dissolve, the water acquiring a strongly acid reaction.0.2574 Gram, suspended in hot water, required 7.50 C.C.N/10-NaOH for neutralisation, using methyl-orange as indicator, whereasthe same weight of the compound C,,H,,*NH*C,H,,HCl requires7.58 C.C. N / 10-NaOH.The acetyl derivative, C,,H,,=N(CH,*CO)*C,H,, was prepared byboiling 1 gram of the amine with 4 grams of acetic anhydride forfour hours. The excess of anhydride was removed by allowing theproduct t.0 remain in a vacuum over a concentrated solution ofpotassium hydroxide, and the residue crystallised from methylalcohol containing a very little water :274-290" ........... 17 '7 ,, I Untlistilled residue ... 3.0 ,,C = 83.35 ; H = 12.24AMINES FROM CARBOXYLIC ACIDS. PART I, 24390.2008 gave 7.5 C.C.N, (moist) at 27*5O and 766 mm.C,,H,,ON requires N = 4.06 per cent,Acetopentaclecylanilicle is very readily soluble in all the commonorganic solvents, and crystallises from methyl alcohol containing alittle water in hair-like needles, melting at 30*5-31'5°.The nitrosoamime, C,SH,,*N(NO)-C,H,, was prepared by addinga solution of 1 gram of the amine in 8 C.C. of concentrated sulphuricacid to a dilute solution of sodium nitrite, the latter being keptin considerable excess, as described for the preparation of thenitrosoarnine of heptadecylaniline (p. 2437). The crude nitroso-amine was purified by crystallisation from met.hyl alcohol :N=4*14.0.1420 gave 10.2 C.C. N2 (moist) at 16O and 768 mm.C21H,,0N2 requires N = 8.43 per cent.Phenylpentadecylnitrosoamine is readily soluble in ether, chloro-form, light petroleum, acetone, or benzene in the cold, and crystallisesfrom methyl alcohol in glistening, flat needles, which melt at 49O,and have a, light fawn colour.A small quantity of the nitrosoaminewarmed with phenol and concentrated sulphuric acid gave a deepblue solution, which, on dilution, gave a red, opalescent liquid,turning blue on being rendered alkaline.N = 8.46.Preparation of a-A niEino m yris tic A cid.Thirty grams (1 mol.) of a-bromomyristic acid and 32 grams(38 mols.) of aniline were heated together in a flask immersed inboiling water for eight hours. The product was worked up asdescribed for the preparation of a-anilinostearic acid (p. 2435), andthe acid purified by crystallisation from a mixture of alcohol andet'hyl acetate, from which it separated in nodular aggregates meltingat 142-143O (compare Hell and Twerdomedoff, Ber., 1889, 22,1748).(Found, N=4.79. Calc., N=4.39 per cent.)Tridecylaniline, C,3H27*NH*C6H,.The a-anilinomyristic acid was heated in quantities of 5 grams ina flask immersed in a metal-bath exactly as described for the pre-paration of heptadecylaniline and pentadecylaniline (pp. 2435,2437), the course of the decomposition being similar in all threecases. The product resuIting from t,he action of heat on 16 gramsof anilinoniyristic acid was distilled under 35 mm. pressure :240-245 "... .. . . . ,248-255 "... ...... 10.5 grams.The fraction 248-255O was redistilled under 35 mm.pressure,few drops only. 260-280" ... .. . . . . . . . ...Undistilled residue ... 1.7 ,, 1 *5 grams. 17 u 2440 PREPARATION OF SECONDARY AMINES.when 9.8 grams, boiling at 250-255O, were obtained, which solidifiedto long, flat needles, melting at 23-24O. This corresponds with a71 per cent. yield of the theoretical. A portion boiling at 251Owas collected separately for analysis :C= 82-65 ; H = 11.99. 0'1512 gave 0.4582 CO, and 0.1632 H,O.0'2052 ,, 9.6 C.C. N, (moist) at 15O and 766 mm. N=5-52.C19H3N requires C = 82-91 ; H = 12.00 ; N = 5-09 per cent.Tm'decylaniline is readily soluble in alcohol, ether, benzene,chloroform, acetone, or light petroleum, and crystallises fromrectified methyl alcohol in long needles, melting at 23-24O.Itis insoluble in water or hydrochloric acid, but dissolves readily inconcentrated sulphuric acid.The hydrochloride, C,3H27*NH*C6H,,HC1, was prepared by passingdry hydrogen chloride into a solution of 1.5 grams of the aminein 50 C.C. ether until saturated. Light petroleum was then addedto the ethereal solution, and the ether evaporated, when, on allowingthe resulting solution to cool, the hydrochloride separated inglistening thin plates. It is readily soluble in a.lcoho1, chloroform,or benzene in the cold, is insoluble in cold acetone or ether, andcrystallises from light petroleum (b. p. 60-80°) in glistening, thinplates, melting at 94'5-95'5O. When heated with water, it meltsbut does not dissolve, and the water becomes strongly acid.0.3060 Gram, suspended in hot water, required 9.8 C.C. N/10-NaOH, using methyl-orange as indicator, whereas this amount ofthe compound @13H2,*m*C6H,,HC1 requires 9.8 C.C. N / 10-NaOH.The acetyl derivative, C,3H2,*N(CH3*CO)DC6H,, was prepared bythe interaction of the amine and acetic anhydride, as described forthe preparation of the other acetyl derivatives :It boils at 251°/35 mm.0.1852 gave 7.6 C.C. N, (moist) at 1 5 O and 756 mm.C2,H3,0N requires N=4.41 per cent.&4 cetotridecylandide is readily soluble in all the common organicsolvents, and crystallises from its solution in dilute methyl alcoholwhen cooled in a mixture of ice and salt, in flat needles, melting atThe nitrosoarnine, C13H2,*N(NO)oC6H,, prepared in a mannersimilar to the other two nitrosoamines, was crystallised from methylalcohol :N=4*77.31-32'.0.1520 gave 12.5 C.C. N, (moist) at 19'5O and 769 mm.C,gH3,0N2 requires N = 9-21 per cent.I-'henyltridecylnitrosoamilze is readily soluble in chloroform, ether,light petroleum, or benzene in the cold, sparingly 40 in cold alcohol,N = 9.41ENFIELD: THE REDUCTION OF CHLORIC ACID. 2441and crystallises from methyl alcohol in f awn-coloured, glisteningplates, melting at 3 9 4 0 O . It gives a well-marked Liebermann’sreaction, the colour changes being similar to those given by theother two nitrosoamines.CHEMICAL LABORATORY,ST. THOMAS’S HOSPITAL,LONDON, S.E

ISSN:0368-1645    

DOI:10.1039/CT9109702433

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

ENFIELD: THE REDUCTION OF CHLORIC ACID. 2441CCIL - The Reduction of Chloric Acid.By RALPH ROSCOE ENFIELD.THE reduction of chloratw or of chloric acid has been the subjectof a considerable number of investigations. I n general, it hasbeen found that a chlorate, such as potassium chlorate, is readilyreduced by zinc axd sulphuric acid, but according to Tommasi(Conzpt rend., 1903, 136, 1005) the salt is not reduced by sodiumamalgam in acid, alkaline, or neutral solutions, whilst, accordingto Hendrixson ( J . Amer. Chem. SOC., 1904, 26; 747), the sameagent has a slight reducing action.Experiments performed in repetition of this work showed thatin presence of excess of a strong acid the chlorate was readilyreduced by sodium amalgam, whilst even in alkaline solutionreduction could be brought about by >he introduction of othermetals, such as platinum, copper, iron, etc.I n the latter case theeffect of addition of one of the metals may be regarded as beingdue to its influence on the electric potential of the hytirogen evolved.The values of the E.M.F. were determined of a cell containing asolution of potassium chlorate, in which sodium amalgam was usedas the anode, and a series of other metals as cathode, and themetals tabulated in the order of the numbers obtained, namely,platinum, copper, iron, nickel, lead, zinc, mercury. It was foundthat potassium chlorate was reduced when a cathode giving a highvalue of the E.M.F. was used, .whilst reduction did not take placewhen the latter fell below a certain value.I n alkaline solution therefore reduction appears to depend onthe activity of the hydrogen used as measured in terms of electricpotential, a result which is in agreement with those of Tafel(Zeitsch.physikal. Chenz., 1900, 34, 187) and others.In acid solution, however, the conditions are more complex, andother factors than the activity of the hydrogen are involved. Byaddition of excess of sulphuric acid to a solution of potassiu2442 ENFlELD: THE REDUCTlON OF CHLORlC ACID.chloratc, reduction is easily effected with sodium amalgam. I f , onthe other hand, a dilute solution of chloric acid prepared by theaction of sulphuric acid on barium chlorate, and free from anyother acid, is acted on by sodium amalgam, reduction is not effected,whilst in the presence of other strong acids reduction takes place.Similar results were obtained by employing other reducing agents ;methyl alcohol, for example, gave no reduction after being left incontact with a dilute solution of chloric acid for a fortnight,although in the presence of sulphuric acid reduction was readilyeffected.Similarly, Burchard (Zeitsclz. physilcal. Chem., 1888, 2,823) has shown that mixed dilute solutions ( N / 5 0 or N/100) ofchloric and hydriodic acids produce no iodine after keeping forseveral days. The case is therefore one of some complexity, andit is evident that the presence and concentration of hydrogen ionsis an important factor in the reaction. The following experimentswere undertaken with a view t o the elucidation of this point.The question of the interaction of chloric acid in a solution con-taining some oxidisable substance has been the subject of a numberof investigations.Burchard (Zoc. cit.) investigated the action ofchloric, bromic, and iodk acids on hydridic acid. He found thatthe reaction with chloric acid was very much slower than in thecase of the other two acids, and that in order that it should proceedwith a sufficient velocity it was necessary that the solutions shouldbe so concentrated and the time of action so long that the exactnature of the reaction could not be determined. The presence ofother acids in these reactions which did not take part in thereaction was found to have an accelerative effect in proportion tothe “strengths” of the acids.Pendlebury and Seward (PTOC.Roy. SOC., 1889, 45, 396) investi-gated the reaction between chloric, hydrochloric, and hydriodicacids. They found that dilute solutions of chloric and hydrochloricacids, when mixed together, slowly evolve chlorine and oxides ofchlorine, that the rate varies with the quantity of chloric acid inthe first place directly, as it is the substance decomposed, and inthe second place with a small acceleration proportional to thequantity. Further, variation in the quantity of hydrochloric acidhas an effect (1) of a secondary order as above, namely, accelerative,and (2) an effect both primary and secondary on the decompositionof chloric acid by hydrochloric acid.Schlundt (Amer. Chern. J., 1895, 17, 754) showed that inthe reaction between potassium chlorate, potassium iodide, andhydrochloric acid, the effect of increase of concentration ofpotassium iodide was about the same as an equivalent increase inconcentration of potassium chlorate, but increase of the acid causeENFIELD: THE REDUCTION OF CHLORIC ACID.2443a greater increase in velocity. He further investigated the influenceof other acids, and found that they exerted an accelerative influencein the order : hydrobromic, hydrochloric, nitric, and sulphuric.Bray (J. Physical Chem., 1903, 7 , 92) found that the rate atwhich iodine is liberated from a mixture of potassium chlorate,potassium chloride, potassium iodide, and hydrochloric acid is pro-portional to the concentration of the chlorate and to the squareof the concentration of hydrogen ions, and is a linear function ofthe concentration of chlorine and of potassium iodide; this corre-sponds with the equations :C10, + C1+ 2H = CI'0,H + ClOH,C10, + I + 2H = C1OZH + IOH,followed by instantaneous oxidation of the hydriodic acid by theirproducts.A similar investigation was ma-de by Sand (Zeitsch.physikal.Chem., 1904, 50, 465), who measured the rate of liberation ofchlorine from a mixture of potassium chlorate and hydrochloric acida t 70°, and found the reaction t o be quinquemolecular, correspond-ing with the equation :C10, + 2H + 2C1= C10 + 2HOC1,the hypochlorous acid then reacting instantaneously with hydro-chloric acid to produce chlorine. On the other hand, Luther andMcDougal (Zeitsch.physikal. Chem., 1906, 55, 477) find that thereaction velocity of a mixture of chloric and hydrochloric acids isinversely proportional to the square root of the concentration ofchlorine, and consider that the reaction :ClO, + 2H + C1= ClO, + &Clz + HZOis involved.It is evident from the above that the decomposition of chloricacid is not of a simple nature, especially in view, also, of theunsatisfactory results obtained when it is attempted to apply theordinary equations for the order of reactions to this decomposition.I n this it is analogous to the case of bromic acid investigatedby Ostwald, Meyerhoff er, and others.It seemed probable t~ the author of the present communicationthat the complexity of these reactions was due to the nature ofthe accelerative influence of the acid, other than chloric, presentin solution.Consideration of some of the preliminary experimentsquoted above led to the hypothesis that the reduction ofchloric acid might involve the decomposition of the non-ionisedmolecule of cliloric acid as the first stage of the reaction. If thiswere the case, addition of a second acid should increase the velocityof reduction of chloric acid by suppressing its ionisation, and con-sequently increasing the concentration of non-ionised chloric acid2444 ENFIELD: THE HEDUCTION OF CHLORIC ACID.It was shown by Burchard and by Schlundt that the effect ofadding acids, such as sulphuric and nitric, was to stimulate thereaction in the order of the strengths of the acids.In view ofthe considerations just mentimed, such stimulating effect maybe due (1) to the mass-action of the second acid in suppressing theionisation of the chloric acid, or (2) t o the purely catalytic influenceof the hydrogen ions, the concentration of which is increased byaddition of the second acid, or (3) to both. Moreover, whenhydrochloric acid is the second acid employed, and the solutionsare moderately concentrated, the conditions are still further com-plicated, since the hydrochloric acid has apparently both a primaryinfluence (that is, it takes part directly in the decomposition ofthe chloric acid) and a secondary (catalytic) influence.The following experiments on the velocity of reduction of chloricacid were made with the view of elucidating the nature of thestimulating effect of the second acid.Considerable difficulty wasexperienced in finding a suitable reaction owing to the extremeslowness of the decomposition, chloric acid being very much morestable than bromic acid a t the same concentrations, and for thisreason it was found impossible to use the reaction with hydriodicacid, which has been much investigated in the case of bromic acid,and which otherwise would have been comparatively easy t omeasure.EXPERIMENTAL.Preliminary experiments were made on the reduction of chloricacid with methyl alcohol in the presence of silver nitrate and asecond acid, and determining the extent of the reaction by weighingthe silver chloride formed.Experiments were made in which thestrength of the second acid was varied, and it was found that thevelocity of reduction increased with increase of the concentration ofthe second acid added, and that the accelerating influence of theacids was in the order of their strengtihs.It was therefore attempted to establish a numerical relationbetween the acceleration due to the acid added and its affinity-constant, by measuring the velocity of reduction of chloric acid inpresence of various accelerating acids.In the following experiments, two reactions were measured, onein comparatively concentrated solutions (normal) and at com-paratively high temperature ( 3 5 O ) , and the other at lower con-centrations and temperature (decinormal and 25.). In both casesit was found that the measurement of the reaction was a matterof considerable difficulty, and that therefore a high degree ofaccuracy was impossible, but it was hoped that the results would bENFIELD: THE HEDUC'L'ION OF CHLORIC ACID.2445such as to indicate a definite rclatim between the acceleration and" strengths " of the acids.The first reaction was that of chloric acid and methyl alcohol, andwas conducted in the following manner.A mixture of 20 C.C. of N-chloric acid, 10 C.C. of methyl alcohol,and 70 C.C. of lV-acid was placed in a tube which was kept in athermostat at 3 5 O . From this, 10 C.C. were withdrawn everytwenty-four hours, neutralised with chalk, filtered, washed, andthe filtrate titrated with N / 100-silver nitrate solution.Two experi-ments were made for each acid, and the mean of the two readingswas taken.A blank experiment was then made in which the catalysing acidwas replaced by water, and the velocity of the reaction was foundto be practically zero. The following table gives the readings forthe four acids, nitric, sulphuric, benzenesulphonic, and oxalic(assuming in the latter case that the oxalic and chloric acids donot interact under these conditions), where x=the amount ofreactlon in terms of 0.1 C.C. N/lOO-silver nitrate, being in each casethe mean of two'readings, and the time is given in days.Sulphuric Acid. I Nitric Acid.Time. 2. Acceleration.1 29'5 -2 54.5 25 -03 77'5 24-04 100 -0 23 55 128.0 34.66 152.0 24 -578 201.5 24 -5Mean acceleration (HNO, = IOO), 100.- -Time.2. Acceleration.1 17.5 -2 28.0 1 0 53 38.5 10.54 48 *O 10'15 57 -0 9 '96 68 '0 10 -178 89-0 10'2Mean acceleration (HNO, = loo), 42.- -Benxenesulphonic Acid. I Oxalic Acid.Time. X. Acceleration.1 19 -2 33 14.03 43 12'04 59 13.35 72 13'267 94 12.5Mean acceleration (HNO,= loo), 53.- -,I Time. 2. Acceleration.I 1 6 I -2 8 2.03 8 1 '04 13 2.35 13 1 - 86 14 1.67 20 2.321 2 *1 I 1 8 1 Mean acceleration (HNO,=100), 7.8I n the blank experiment, without addition of acid, it was foundthat after thirteen days the amount of reaction was equivalentto 0.5 C.C. iV/lOO-silver nitrate solution, and therefore in calculatingthe accelerations due to the presence of t.he above acids at anytime it was assumed that the corresponding amount of action in theblank experiment was negligible.The '' acceleration '' may beregarded therefore M equivalent to the velocity in each case. Th2446 ENFIE1.D: THE REDUCTION OF CHLORIC ACID.values of the acceleration at any particular time were found bysubtracting from the amount of reaction which had taken placeat the end of that time, the corresponding amount at the end ofthe first day, and dividing by the time. The amount of reactiontaking place during the first day was neglected owing to theunavoidable presence of a trace of chloride at the beginning ofthe experiment.The acceleration constants thus obtained are in the order ofthe strengths of the acids used, although not numerically com-parable with the affinity-constants.Close agreement, however, wasnot to be expected, owing t o the conditions of concentration andhigh temperature used. It was found impossible to obtain satisfac-tory results with other acids, owing in some cases to the conditionsof experiment, and in others to the reaction being too slow tomeasure.The second reaction studied was that of chloric acid and ferroussulphate, which took place in decinormal solution with sufficientrapidity at 2 5 O to be conveniently measured. The experimenttube contained a mixture of 20 C.C. of N/lO-chloric acid, 20 C.C. ofN/Ei-ferrous sulphate solution, and 60 C.C. of N/lO-acid. Aftermixing, 10 C.C. were withdrawn and titrated with potassium per-manganate, the titration repeated, the experiment tube containingthe mixture placed in a thermostat at 2 5 O , and the time noted.After a period of forty-five minutes, 10 C.C.were withdrawn andtitrated. The reading was repeated, and the mean value recorded.Some difficulty was experienced in obtaining a good end-point inthe permanganate titration owing to the presence of a smallquantity of hydrochloric acid produced by the reduction of thechloric acid. It was attempted to use a large excess of manganesesulphate, but extreme difficulty was experienced in judging thecolour in presence of the solution of this salt, and it was finallyfound more accurate to dilute the solution largely with waterand to titrate in a porcelain dish, judging the colour by lookingthrough a depth of the liquid.The solution of chloric acid was prepared as before by the actionof sulphuric acid on barium chlorate, the barium sulphate beingremoved by filtration. The solution was tested for excess of sulphateor barium, and then standardised with N-potassium hydroxide.The ferrous sulphate was prepared by dissolving pure crystals ofthe salt in water free from air, the solution being kept out ofcontact with air under a layer of benzene.A blank experiment was made in which the accelerating acidwas replaced by water, and the acceleration due to each acid wasfound by subt'racting the amount of reaction which had takeENFIELD: THE REDUCTION OF CHLORIC ACID.2447place in time T in the blank experiment from the correspondingamount in each of the "acid" experiments. The results weretabulated, and the acceleration constants reduced to HCl= 100.The results obtained were as follows, where A =original con-centration of ferrous sulphate in terms of 0.1 C.C.N/lOO-per-manganate, and is the mean of two readings, and xl, x2 ?re thereadings for the concentration after time T, X being the mean;T = forty-five minutes.Acid.No acid ............HC1 ..................H Br ..................HNO, ...............C,,H;SO,H .........CCl;CO,H .........CHCI;CO,H ......CH,Cl*CO,H ......71,80, ...............A.426.5422'0430.0422'5425'0426.0425'0427.5426.0XI. 2*.375 376238 247245 247265 2662 i 9 286257 256265 265328 329362 360X .375.5247-5246.0265.5282.5256.5265'0328.5361 -0Accelera-A - X.tion.51.0 -174.5 123.5184'0 133'0157-0 106.0142-5 91.5169.5 118-5160'0 109.099.0 48-065.0 14'0Accelera-tion,HC1= 100.100108867497883911-The acceleration constants thus obtained, compared with thecorresponding affinity constants found by the hydrolysis of methylacetate, are as follows:Accelerationconstant. Hydrolysis.HCI ........................... 100 100HEr .......................... 108 98 or 111 by sugar inversion.HNO, ........................ 86 92H,S04 ........................ 74 74C,H;SO,H .................. 97 98CCI3*CO,H .................. 88 68CHCl,*CO,H .............. 30 23CH,Cl*CO,H ...............11 4'3The agreement between the acceleration constant and affinityconstant is as close as would be expected, considering the natureof the reaction investigated, except in the case of the chloroaceticacids. It was thought that the high result obtained in each casewith these acids might be due to the presence of hydrochloric acidformed by their hydrolytic decomposition, but the solutions weretested after the experiment with silver nitrate solution, and gave noprecipitate.The effect of variation in quantity of the catalysing acid wasthen examined with the view of ascertaining whether the velocitywas affected in any marked degree by the presence of smallquantities of the acid.The experiments were conducted as in the last series.The experiment tube contained a mixture of 20 C.C.of N/10-chloric acid and 20 C.C. of N'/5-ferrous sulphate solution, and avariable quantity of sulphuric acid dissolved in 60 C.C. of water,making a total of 100 C.C2445 ENPIELD: THE HEDUCTlON OF CHLORZC ACID.The following results were obtained :No. of mols. H,SO, Accelera-t o 1 mol. HC10,. A. 21' 4. X. A - X . tion.3 425 279 286 282.5 142'5 91 *5i!! 418 343 345 344 74 23.0D 417'5 354 356 355 62-5 11-54iT 417 360 361 360.5 56.5 5.5Finally, experiments were made on the influence of neutral saltson the velocity of the same reaction. The conditions of experimentwere the same as before; the experiment tube in each case contained20 C.C. of N/lO-chloric acid, 20 C.C. of N/5-ferrous sulphate solution,and 60 C.C.of an N/lO-solution of the salt.The following results were obtained :Accelera-Salt. A . xl. z,. X . A - X . tion.KCl .................. 415.0 363 364 3635 51-5 0 -5KNO:, ............... 411'0 357 357 357'0 54.0 3.0Ns,SO, ............ 413*0 374 375 374.5 3 8 5 - 12.5K,SO, ............... 416.5 379 378 378.5 38.0 - 13.0IWlO, ............... 398.0 263 265 264.0 134-0 83.0NaCIO, ............ 410.0 276 278 277.0 133'0 82.0It is evident from these results that a neutral salt containing nocommon ion accelerates the reaction to a very small degree, whilst. asalt containing a C10, ion accelerates it very considerably. I norder further t o examine the reaction with a solution of potassiumchlorate, an experiment was made under the same conditions asbefore, in which no chloric acid was present, the experiment tubecontaining 20 C.C.of A7/5-ferrous sulphate solution and 80 C.C. ofN/lO-potassium chlorate solution, but it was found that the amountof reaction after forty-five minutes was practically nil. Theinfluence of potassium and sodium sulphates on the velocity of thereaction is somewhat remarkable. Both salts retard the reactionand approximately to the same degree. This may, perhaps, be dueto the formation of less easily oxidisable complex molecules withthe ferrous sulphate analogous to ferrous ammonium sulphate.Summary and Conclusions.(1) Chloric acid is not reduced by sodium amalgam in dilutesolutions, but 'is reduced in the presence of strong acids.(2) A dilute solution of chloric acid in the presence of methylalcohol is not reduced even when the mixture is kept for severaldays, but in the presence of strong acids reduction takes place.(3) The rate of reduction of chloric acid by methyl alcohol isextremely slow even in normal solutions, but is accelerated bENFIELD: THE REDUCT~ON OF CHLORIC ACID.2449addition of strong acids, the order in which these acids acceleratethe reaction being that of their relative “ strengths.”(4) The reaction between chloric acid and ferrous sulphate indecinormal solution is accelerated by the addition of other acids,the acceleration produced being a function of the ‘‘ strengths ” ofthe acids.(5) The same reaction is accelerated in a smdl degree by neutralsalts containing no ion common with any taking part in thereaction.It is accelerated in a large degree by chlorates, and isretarded by sulphates.It has been suggested above that the accelerative influence ofthe second acid may be of two kinds, and hence that this influencemay be open to two theoretical interpretations. On the one hand,the reaction may be “ ionic,” the reduction being that of the C10,ion, and the influence of addition of other acids being due to thepurely catalytic influence of hydrogen ions. Qn the other hand,the primary reaction may be the breaking down of the non-ionisedchloric acid molecule, which would be accelerated by the additionof other acids in virtue of the mass-action of the hydrogen ions.With regard to the addition of neutral chlorates, i t has been shownabove that these accelerate the reaction to a considerably greaterdegree than salts containing no ion common with any of thosetaking part in the reaction.This accelerative influence is similarlyopen to both interpretations; it may be due to the mass-action ofthe C10, ion by which the concentration of the non-ionised chloricacid would be increased, or, since hydrogen ions are present, it maybe due to the increase of total concentration of the substance under-going reduction, namely, the C10, ion. It is evident, however,that free acid is essential to the reaction, since a neutral chloratedoes not appear t o be affected by the reducing agents employed.Hence, if the reaction is “ionic,” it must be assumed that in theabsence of catalysing hydrogen ions, the reaction is too slow tomeasure.With regard to the experiments given in the present com-munication, the most important evidence is in the relation ofacceleration constants to affinity constants. Chloric acid, accordingto the conductivity measurements of Ostwald, is a strong acid havingan affinity constant of 98, compared with 100 for hydrochloric acid.I n view of this, and in view also of the great uncertainty ofbehaviour of strong acids in presence of their salts (and in generalof solutions of mixed strong electrolytes containing a common ion),it is improbable that any close agreement would exist between theacceleration and affinity constants of the acids if the accelerativeeffect were due to the mass-action of hydrogen ions. Hence th2450 SUDBOROUGH AND THOMAS: THE ADDITION OFabove results seem to favour the view that the reaction is an ionicone, and that the accelerative influence of the second acid is dueto the catalytic action of the hydrogen ions.Several attempts were made to devise an experiment which wouldexclude one or the other of the above interpretatlons, such as theuse of a non-ionising solvent, an experiment which would have beenof great value in deciding the point. Although many solventswere tried, however, none was found which would meet the require-ments of the experiment.I n conclusion, I wish to express my sincere thanks to Dr. H. J. H.Fenton for valuable criticism and advice.THE UNIVERSITY CHEMICAL LABORATORIES,CAMBRIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702441

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2450 SUDBOROUGH AND THOMAS: THE ADDITION OFCCLI1.-The Addition of Bromine to UnsntzwatedCompounds. Part II.By JOHN JOSEPH SUDBOROUGH and JOHN THOMAS.IN continuation of the work already published (this vol., p. 715)we have examined the rate of addition of bromine to the followingacids : Cinnamylidene- and allocinnamylidene-acetic a.cid, sorbicacid, &phenyl-Aa-, -A&, and -A?-pentenoic acids, hydrosorbic acid,crotonic, angelic, tiglic, P-dimethylacrylic, and trimethylacrylic acid.The method of procedure was exactly the same as that used in theearlier work, and the carbon tetrachloride and bromine were purifiedin the same manner. A control experiment made with brassidicacid gave values for K varying from 3-0 to 6.9, as compared withthe previous values, 3.1 to 7.4.Although the new bromine andcarbon tetrachloride gave values for brassidic acid which were verysimilar t o the values obtained previously, it was found that whencinnamic acid was used, the values obtained were considerably lowerthan the earlier values, namely, 1-02 x 10-5 to 2.94 x 10-5, ascompared with 0.9 x We have not been able toascertain the reason for this difference, but we have been able toshow that the presence of moisture facilitates the addition ofbromine. This. is best shown in the case of the experiments withcrotonic acid :to 2.6 xK.7 '31 A lou5 t o 13.7 xDry carbon tetrachloride .... .. ............ 4-68 x to 6.16 x 10-6Moist ,, 9 9 .. .. . .. . . .. . . . .. BROMINE TO UNSATURATED COMPOIJNDS. PART 11.2451t (hours). n - x. l / t . r/n(n - 2).0'5 24 -8 4.16 x 10-31.0 23.95 3'511 -5 22-95 3.562'0 22'20 3-40The following table gives a list of ths values of K obtained forthe different acids a t 1 5 O :t (hours). (L - x. l / t . x/a(a - 2).0.5 24'8 4-16 x 10-31 -0 23.5 4 -311 5 22.0 4-512 *o 20 .a 4'92Olefine Acids.Maximum No. of l / t . ./.(a - x).Acids and formula. Series. time. titrations. Minimuni. Maximum.Crotonic, CHMe:CH*CO,H ...... n 189 hours 4 4.68 x 6.16 x l o d 6Angelic, CHMe:CMe*CO,H ...... a 145 .. 4 0'83 x loY4 1'9 x lo-'Tiglic, CHRle:CMe'CO,H ...... a 168 .. 4 1.3 k10-5 9-9 ~ 1 0 - 5fi-Dimethylacrylic, a 6 9 , 3 5.8 x10-3 7-0 xio-3CMe,:CMe'CO,H ............... a 8-5 .. 4 1.1 x10-2 2.2 x10-2CMr,:CHf!O,H ............... b 6 ..4 3.1 xlO-' 7'3 xTrinie t ti ylacrylic,6-Phenyl-A@-pentenoic, a 0.5 ,, 4 3-1 x10-1 3.7 x 1 0 - ICH,Ph*CH:CH*CH,*CO, ... b 0-5 .. 3 6'2 xlO-, 2-2 x10-'6-Phenyl-Ay-pentenoic, a 60 sees. 4 45.7 82.3CHPh:CH*CH2*CH,*C0,H.. . b 31 , . 4 35.5 60 *3Hydrosorbic, a 60 9 , 4 1.3 x102 3.3 x10'CH,Me'CH:CH'CH;CO,H ... b 20 ,, 4 2.4 x102 3.9 x102Diolefine Acids, with Conjugate Double Bonds.Sorbic, a 0.66 hours 3 1 ' 0 3 ~ 1 0 - ~ 6.8 ~ 1 0 Cinnainy lideneacetic a 1.0 ,, 3 2 * 2 1 ~ 1 0 - ~ 2 . 6 3 ~ 1 0 - ~a 1.05 y y 4 2 ' 5 6 ~ 1 0 - ~ 3.1 x ~ O - ~nlloCiiinaniylideneace~ic B 1-25 4 2'9 3.5 x10-,CHMe:CH*CH:CH*CO,H ... b 0'66 .. 4 1'1 X ~ O - ~ 12'2 X ~ O - ~CHPh:CH*CH:CH.CO,H ... b 4.5 .. 4 0 * 9 7 ~ 1 0 - ~ 1.3 x ~ O - ~.........The ap-unsaturated acid, 6-phenyl-Aa-pentenoic acid,CH,Ph CH,*CH : CH* CO,H,combines with bromine very slowly in the dark.Immediately aftermixing, the amount of bromine used up corresponded with 0.5 C.C.of the thiosulphate solution, and even after 190 hours the amountof thiosulphate required was the same. The acid thus combineswith bromine even less readily than does cinnamic acid. Thefollowing values were obtained for the two acids when the additionof bromine was allowed to take place in daylight; the two seriesof experiments were conducted side by side in order that the resultsshould be strictly comparable :Cinnamic Acid (a = 26.15).t (hours). n - x. l / t . x/a(a - z).0.5 16.7 4 *33 x 10-21 -0 12'7 4-051 5 8-15 5.632.0 5.5 7-12452 SUDROROUGH AND THOMAS: THE ADDITION OFThe results prove that in daylight bromine combines with the6-phenyl-Aa-pentenoic acid less readily than it does with cinnamicacid.The points to which we wish to draw attention in connexion withthe results tabulated above are:(1) The values confirm the generalisation drawn previously(p. 719), namely, that aP-unsaturated acids combine with brominefar less readily than the isomerides, in which the double linking isfurther removed from the carboxylic group.(2) The introduction of methyl substituents, attached to thecarbon atoms between which the olefine linking exists, facilitates theaddition of bromine to an appreciable extent.(3) When the acid contains conjugated olefine linkings, one ofwhich is in the a8-position with respect to the carboxylic group, theaddition of bromine takes place more readily than when theaS-ethylene linking alone is present.I n the examples we haveexamined, namely, sorbic, cinnamylideneacetic, and allo-cinnamylideneacetic acids, it is known that the two atoms ofbromine are added on in the a&positions, and the reaction is thusnot strictly comparable with the addition of bromine to cinnamicacid, where the bromine attaches itself at the aP-position.Preparation of the Acids.1. Cinnamyridenemalonic acid was prepared by the methoddescribed by Riiber (Ber., 1904, 37, 2274), with the exception thatthe mixture of equal weights of malonic acid, quinoline, andcinnamaldehyde were kept in a stoppered bottle for three weeksinstead of the two recommended by Riiber.The reduction of thesubstituted malonic acid was carried out according to Riiber’smethod, using pure mercury for the preparation of the amalgam,but the evolution of carbon dioxide and the formation of 6-phenyl-A.P-pentenoic acid, CH,Ph*CH:CH*CH,*C02H, was effected by asomewhat different method, as we had no method of obtaining apressure of 0.15 mm. (Ber., 1905, 38, 2746). The dibasic acid(25 grams) was heated in a sulphuric acid bat,h at 110-115° untilthe evolution of carbon dioxide had ceased, and the product, whichwas slightly coloured, was distilled under a pressure of 10-12 mm.,when the monobasic acid passed over at 176--182O, and solidifiedon cooling. The transformation of the By-acid into a mixture ofa& and 76-unsaturated acids was carried out according to Riiber’sdirections (Zoc.cit., p. 2747). The P-hydroxyphenylvaleric acid wasremoved by making use of its insolubility in hot carbon disulphide,and the oily acid removed by pressing the mixture of acid on aplate. The solid mass, consisting mainly of the 0sP- and y6-acidsBROMINE TO UNSATURATED COMPOUNDS. PART 11. 2453was dissolved in hot carbon disulphide, and, on cooling, crudeup-acid separated. From 150 grams of By-acid, 26 grams of crude&-acid were thus obtained, and after some six recrystallisationsthe acid was quite pure. To obtain the 76-acid, the carbon di-sulphide mother liquor was evaporated to dryness, and the acidtransformed into the sparingly soluble calcium salt under theconditions described by Riiber.The acid obtained from the calcium’salt still contained a@-acid, and this was removed by crystallisationfrom carbon disulphide and mechanically removing the characteristicplates of the y6-acid and crystallising from light petroleum, when11.5 grams of pure acid, melting a t 9l0, were obtained.Twenty-five gramsof sorbic acid were dissolved in sodium hydroxide solution, andthe whole made up to 300 C.C. with water. The solution was trans-ferred to a separating funnel, and placed in a bath at 30-35O.Rather more than the theoretical amount *of 3 per cent. sodiumamalgam was added in small amounts at a time, and the funnelwas shaken vigorously after each addition. The reduction pro-ceeded vigorously at the beginning, but slackened toward the end.The mercury was removed, the solution acidified with hydrochloricacid (1 : l), and extracted with ether. After removal of the ether,13 grams of hydrosorbic acid, boiling a t 103°/9-10 mm., wereobtained. When the distillation was continued, the temperaturerose rapidly, but did not become constant.3. Cinnamylideneacetic and allocinnamylideneacetic acids wereprepare by Liebermann’s method (Ber., 1896, 28, 1441). Thedo-acid was slightly impure, and melted at 115-1 1 7 O .4. The B-dimethyl- and trimethyl-acrylic acids were prepared bythe methods described previously (Trans., 1909, 95, 977).2. Hydrosorbic acid was prepared as follows.We wish t o express our thanks to the Research Fund Committeeof the Chemical Society for a grant which has covered part of thecost of this investigation.THE EDWARD DAVIES CHEMICAL IAABORATORIES,UNIVERSITY COLLEGE OF WALES,ABERYSTWYTH.VOL. XCVII

ISSN:0368-1645    

DOI:10.1039/CT9109702450

出版商:RSC    

年代:1910

数据来源: RSC

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2454 MERTON : THE VIS(I0SITY ANDCCLIIL-The Viscosity and Density of CaesiumNitrute Solutions.By THOMAS RALPH MERTON, B.Sc. (Oxon).IN recent years the viscosity of salt, solutions has been the subjectof numerous investigations, which have mainly been directedtoward elucidating the relation between viscosity and electricalconductivity. Most of the alkaline nitrate solutions have beeninvestigated (Gruneisen, Wiss. Abh. Yhys. Tech. Reichsanstalt, 1904,4, 239; Applebey, this vol., p. 2000, and others). Very little,however, is known of the viscosity of cmium salt solutions, withthe exception of a single investigation on the viscosity of thechloride solution by Wagner (Zeitsch. ph,ysilcaZ. Chem., 1890, 5,31).In the present investigation, the viscosities and densities ofcaesium nitrate solutions of different concentrations have beendetermined at Oo, loo, 1 8 O , and 2 5 O .EXPERIMENTAL.The method used for determining viscosity was that of Poiseuille,that is to say, a determination of the times of flow of the solutionthrough a capillary tube.The precautions which must be observedin order to secure an accuracy of one part in a, thousand by thismethod have been thoroughly investigated by Gruneisen (Zoc. cit.,p. 153) and Applebey (Zoc. cit.), whose method I have followed inthis investigation, and to whom I am indebted for much valuableassistance in the progress of the work. Two viscometers of theOstwald type were used.For viacometem of this type we have:r] solution (A solution - d ) x t solutionr] water (A water - d ) x t water ’where yl is the viscosity, A the density, t the time of flow of theliquid through the capillary, and d the density of air.Gruneisen (Zoc.cit.) has shown that, for viscometers of the typeused, it is unnecessary to apply any correction for the kineticenergy of the liquid in the capillary.The determination of time offered no difficulty, and was measuredby means of a stop-watch reading to one-fifth second, which keptexcellent time throughout the investigation.I n orifer t o prove that the flow of the liquids to be investigatedin the viscometers obeyed Poiseuille’s law, one of the tubes was- ---_______~ DENSITY OF CiESIUM NITRATE SOLU'I?IONS. 2455calibrated by Griinsisen's method, with the experimental arrange-ments used by Applebey (loc.&.). The times of flow of equalvolumes of water through the capillary under different hydrostaticpressures are given in the following table:Excess pressure(in mm. of waterat 18").1'07'322.433'545.055 *777-0a3 .s88 *7110'1134.5149'9Totalpressure.115'4121.7136.8147'9159.4170'1191.4198'2203'1224-5248.9264.3Time(in 1/5th secs.).457343383865356632983091275526632585234021161990Pressurex time.5276i 2805288527352685260527352785250525552655261As will be seen, the value pressure x time is constant within thelimits of experimental error, showing that the flow of liquid throughthe tube obeys Poiseuille's law, and that the tube can therefore beused for comparative measurements between the limits of timeexamined.The second viscometer used in this work wits standardised bycareful comparison with the first.For this purpose a nearlysaturated solution of casium nitrate has unique advantages, as itshigh density and low viscosity cause it to flow through the tubemore rapidly than water. The ratIos of the tdmes of flow 0.f thesolution and water in the two tubes were compared, with thefollowing resuIts :Time of Time of Time of flow of solution.flow, water. flow, solution. Time of flow of water.Standard tube ...... 4802 4020 0.8371Tube 7 ............... 4132 3459 0'8371The constancy of the ratio shows that the second tube obeysPoiseuille's law in exactly the same way as the first.The viscometers were usually cleaned after use by drawing themthrough a considerable quantity of the purest available water.If,however, the (( water constant " or time of flow of water had changedit was usually redetermined for one of the viscometers after eachsolution), or if any dust had lodged in the capillary, it was cleanedwith a mixture of nitric acid and a drop of alcohol, followed bywater. The viscometers were dried by drawing dust-free airthrough them in a hot-air bath.I n this connexion it may be mentioned that the purity of theair in the room in which the viscometers are dried is of considerableimportance. 'On one occasion there was a certain amount of amyl7 x 2456 MERTON: THE VISCOSITY ANDacetate vapour in the room in which the viscometers were dried,owing to some celluloid varnish containing amyl acetate which hadbeen used there.I n consequence of this, anomalous results wereobtained, and it was not until the drying apparatus was removedto another room that the viscometers again gave their originalwater value.Mat em’als Used.-The msium nitrate used in this investigationwas very kindly lent by the Earl of Berkeley. It was examinedspectroscopically, and n’o trace, of any impurity could be found. Thewater used was the best dust-free water obtainable (the electricalconductivity varied from 1 x 10-6 t o 2 x 10-6 mhos.). I n makingup a solution, the approximate quantity of salt required was placedin a quartz crucible, and heated for about four hours in % quinolinebath at 1 7 0 O .It was then weighed and dissolved in a known weightof water.Determination of Den.sity.-For the determination of density, apyknometer containing about 12 C.C. of the solution was used. Twosettings and two fillings were taken, the pyknometer being weighedagainst a counterpoise. The pyknometers were “ s e t ” in theconstant temperature baths in which the viscosity measurementswere made. For the densities at Oo, two pyknometers were used,with a small bulb above t’he capillary to allow for the expansionof the liquid on removing it from the ice, and a glass cap t o preventevaporation. They were set in a jacketed vessel containing crushedice.Constant Temperature Baths.-The experiments at loo, 1 8 O , and25O were performed in large glass-fronted baths containing about25 litres of water, vigorous stirring being obtained by means ofglass stirrers driven by an electric motor.The temperatures ofthe baths were verified by means of a standard Goetze thermometer.The 25O bath was heated by a small gas flame, which was governedby a large spiral toluene regulator (Lowry, Trans., 1905, 87, 1032).The 18O bath was heated by a 16 c.p. electric filament lamp placedin a bath close to the stirrer, and governed by a spiral electricregulator.The loo bath was identical with that at 1 8 O , except that itcontained in addition it coil of metal tubing, through which waterwas run, to act as a cooling apparatus. No variation in the tem-perature of these baths could be detected on the thermometerdivided in 1/50°.The loo bath, with which some trouble wasanticipated, was particularly carefully examined with a Beckmannthermometer, but no variation as great as 1/500° could be detected.The experiments at Oo were performed in a large Dewar vacuumvessel, containing crushed ice and water vigorously stirred. A tThe solutions were filtered to remove dust particlesDENSITY OF CXSIUM NITRATE SOLUTIONS. 2457this temperatur? rapid stirring was found to be essential in orderto prevent accumulation of warmer water at the bottom of thevessel. I n the event of a small variation of temperature occurring,a calculated correction can be applied. This correction was foundto be about two-fifths second for l/lOOo.It is probable that owingto the difficulty of maintaining constant temperature, the resultsa t Oo are not so accurate as at other temperatures,Density Results.-The results of the density determinations aregiven in the following tables. As will be seen, the weighingsusually agree to within 0.0001, or at most 0*0002, milligram, andtherefore the errors in the densities do not exceed 0.00002. Values of(A - 1) - Concentration x Constant are given, from which a sensitivecurve can be drawn.Densities at Oo.Parts ofof water. 1. 2. sp. gr. A;. 0.00'74.Mass of solution inczsium nitrate pyknometer.in 100 grams <-k-. Mean (A - 1) - PX0 12'4743 14.0425 1 0'99987 - 0.000131 '00751'978414'150714 -1 5 0714.2537{14*1507} 1.00770 1.00757 +O'OOOlO{ 14.2537] 1*01504 1'01491 +O-000274.0208 13.8832 -14.4690 ' 1.03937 1.03023 + 0.000486-2489 14.1033 14-6981 1-04668 1-04654 + 0'000308.3724 14.3110 14.9144 1-06209 1.06195 + O*OOOOODensities at loo.Parts of caesiumnitrate in 100 gramsof water.01-04672.18493'23615.73368.889112.069814.3040Mass ofsolution inpyknome ter.12.577812.8801 -13 -6 74 113.674213.6741Mean sp.gr.11 -007821,016261 '024031'042191 -064741.087161 '1 0237A abs.0,999731-007551 001 5 981 *023751'041911-064451.086871 *lo207(A - I) -- P X- 0.000270'0071357.+ 0*00008+ 0 *00039+ 0*00066+ 0~00100+ 0'00102+ 0 -00072458 MERTON: THE VISCOSITY ANDDensities at lao.Parts ofcaesium nitrate pyknometer.in 100 grams <-A-- Meanof water.3. N. sp. gr.0 12.5674 8.8160 11.0060 { 12*6611} 1.00745Mass of solution in12.661012'66109'65691 *015'171,022981.036981.08820Densities at 25O.Parts of Mass of solution incEsium nitrate. pyknometer.in 100 grams , - = = h - , Meanof water. 3. A?. sp. gr.0 12.5502 8'8043 11'00602.14153'12995.06776'58829'656912 '376016.63551.007391 '0 156 61.022811 936731 '04 7 431.068941 -087601.11625(A - I) - PX0'99862 - 0'00138A abs. 0'0070074.- 0'000991.01437 - 0*000631.02157 - 0'000361 -03555 + 0.000041.04633 + 0.000171'06805 + Oflo0381 -08671 +, O*OOOOO1.11525 - 0.00132(A - 1) - P X0.99707 - 0'00293A abs. 0'0068215.1'00443 - 0.002431'01268 - 0'001931.01981 - 0.001541'03369 - 0'000881'04436 - 0*000581'06580 - 0*000071'08441 - O*OOOOO1'11298 - O*OOO5DENSITY OF CAESIUM NLTRATE SOLUTIONS.2449T~i.scosity R esults.-The results of the viscosity determinations aregiven in the following tables. The results are probably correct tor f 2 in 5000 at 1 8 O , 2 5 O , and loo. A t Oo the errors are somewhatgreater, but the values given are probably correct to 5 3 in 5000.I n Fig. 1 the relative viscosities are plotted against the con-centrztion. Values of (1 - y) - concentration x K are given, fromwhich a sensitive curve may be drawn. The viscosity in absoluteunits has also been calculated, the absolute values of water beingtaken from Thorpe and Rodger's values (Phil.Trans., 1894, A ,185, 397)-At 0" = 0.01778 At 18" = 0*010510At 10" = 0'013025 At 25" = 0.00891PIG. 1.1 '00000.98000.96000'94000 -92000 5 10 15Grams of eaesizm nitrate in 100 grams of water.Disczcssion o i Results.It will be seen that at all temperatures the viscosity of caesiumnitrate solutions is less than that of water. It conforms with therule found for ot,her salts, in that the decrease of viscosity forunit quantity of salt decreases with increase of concentration.The discovery of Griineisen (Zoc. cit.), that the viscosity curves ofall ionised solutions exhibit a change of curvature at the diluteend, has been confirmed in the caie of cesium nitrate. This canbe seen in curves in which viscosity is plotted against concentration,but it can be better appreciated by plotting (1 - y ) / N (where N isthe normality) against :+J\/N.I n Fig. 2, l - q / N is plottedagainst 32/normality at 1 8 O . It is more convenient to plot 3Jxthan N , as in this way the dilute end is more extended. It willbe seen that the errors in the determination of ( l - q ) / N increasevery rapidly towards the dilute end. For example, in a solution______rel.00376007tO144015040303704403Of32091.004270007 821.024031,042191.064741.08716lo237Time nf flow of solutionTime of flow of waterby viscometer No.5 6 7 7 - 0.9923 0'9923 -0.9826 0-9826 o - g m - - - 0.9729 0'97300-9320 0'9320 0.9318 0,9318 - 0-9042 0'9042 0'09440.8703 0.9703 0.8703 -0.9648 0.9648 0'9651 -Viscosity at 1090.9928 0.9928 0.9928 -0.9857 0.9857 0'9854 -0.9234 0.9234 0.8236 -0.8565 0.8563 0.8561 -0.8355 - 0-8355 -- - 0 9557 0 95550.8880 - 0.8879 0.8879Mean q(relative).0.99600.99010'98410'97930'96020.94410.92440.99700.99320-9'i'SS0.96250-94540.93090 92111 - v/N,OmO15910'019330 '020890.020730 *020050'019520'019080'10270-12780'13230.13470.13030-12500.1228q abs.0 '017 7090 -01 76030.0174970 -0 1741 10.0170630 -0 I67860 *0164360 -01 29860.0129360*0127460.0125360 -0 1231 40.0121280-01 1997(1 -7))-Px0.0093.- 0 '0004 + 0*0008 + 0 *0024 + 0-0028 + 0.0038 + 0 *0026 + 0 -0000(1 - v ) - P x0'005523- 0~0001- 0*0010 + 0*0035 + 0.0059+0*00653- 0.0025 - 0~000Viscosities at 18'.re].00333007451.015771.02298036981.04778069530888116791.003311.00739015660228103673047431.06894087601.11625Time of flow of solutionTime of flow of waterby viscometer No.50'99520.98850.97460.96230.94030.92380'89400.87020.83715-0.96230.94030.92380-89400-87020.83717 70-9954 0'99540-9886 0.98860.9746 -0'9622 -0'9404 -0'9242 -0.8938 -0'8iOO -0.8371 -Viscosity at 25O.0.99560.98960.97750'96620-94620.90480.88300.8529-0.9956 0.9954- 0.9897 - 0,9773 - 0-96620.9462 0.94640,9324 0.93190'9048 0.90480.8529 0.85220.8830 -Mean n(relative).0'99860.99600-98990.98440.97520.96810.95610.94700.9347- 0 99880.99700-9773 0.99260.9662 0.9882- 0,98110.9319 0.9761- 0.9671 - 0.9604 - 0.9518-1 - q/ N.0.060500'078270.093860'100190~100200.100530,097120.093770 -088920.51850,58710.68770,75780,76360.75320-72780.70060.6583q abs.0 -01 04 950-0104680 *0104040.0103460'0102490 -01 01 7 50'0100490 *0099530 -0093360'0088990 -0088830.0088440'0088040,0087420.0086970.0086170.0085570'008480( l - ? l ) - P x0-004283.-0'0003+ 0-0031-1-0-0037 j; + 0 '00250.0-0.0071 51- 0.0005+of)oo9 0'0022 0 m!a * c3H(1 - q ) - P x0.0032.+0*0006 0+0*0018 5+0.0027 + 0.0028 + 0-00200 .oo-0*0050-0'0002 5-0'0002 2k PQ, 2462 VISCOSITY AND DENSITY OF C&SIUM NITRATE SOLUTIONS.with a relative viscosity of 0.9980, (1 -7) would be 0.0020, so thatan error of 0.01 per cent.would produce an error of about 4 percent. in the value of 1 - q / N , whereas if the viscosity were 0*9200,a similar error would alter 1 - ~ / L V by less than 0.125 per cent.It would be of great interest to discover, if possible, the valueof 1 - q / N for infinite dilution, but', as has been shown, the errorsincrease so rapidly towards the dilute end that it becomes impossibleto form any estimate.Gruneisen (Zoc. cit.) has proposed the formula:91 - 1 N = A i + B( 1 - i) + CN,where .i. is the ratio L / L , , L and Lo being the molecular electricalconductivities at concentrations N and 0, and A , B, and C areFIG. 2.0 -3 0'5 0.7 0 -9JiVormality (weight).constants depending on the nature of the salt.Gruneisen hasobtained fairly good agreement in his results between the foundvalues of 7 and those calculated by this formula. I have not beenable to find any determinations of the elect,rical conductivity ofczsium nitrate solutions, and have therefore been unable to makeany attempt to apply the formula to my results.From the absolute values calculated from Thorpe and Rodger's(Zoc. cit.) values for water, it will be seen that the change ofviscosity produced by a rise in temperature decreases with increasingconcentration. Thus, 7 parts of caesium nitrate in 100 parts ofwater lower the viscosity about 7.5 per cent. at Oo, but less than3 per cent. at 25O.The general form of the viscosity curve is precisely what wHOMOGENEOUS DECOMPOSITION OF OZONE.2463should expect from the position of cEsium in the periodic system,a comparison with the viscosities of lithium, sodium, and potassiumnitrates, taken from Griineisen’s paper, showing that, qualitatively,the visoosity changes follow the classification of the elements in thoperiodic system. I f we may assume that the viscosity of a solutiondepends on the mean size of the molecules and ions, we shouldinfer that of the alkali metals the msium ion is the smallest, inaqueous solution, that is to say, it has a smaller number of watermolecules attached to it than the ions of the other alkali metals.In agreement with this, the caesium ion is known to possess thelargest ionic mobility.Su.mmary.The viscositlies of czesium nitrate solutions have been investigatedat Oo, loo, 18O, and 2 5 O . The results confirm in every respect thegeneral principles discovered for other salt solutions.The densities of the solutions at these temperatures have beendetermined. I n these determinations, no abnormal results havebeen found. The change of density per unit quantity of saltdecreases slightly with an increase of concentration.The effect of temperature on the viscosity has been examined,and found to decrease with increasing concentration.With respect, to the viscosity of the nitrate solutions, caesiumoccupies a position a,mong the alkalis in accordance with its positionin the periodic system.I n conclusion, I should like to express my thanks t o Mr. H. B.Hartley and Mr. D. H. Wagel for tho kind assistance and advicethey have given me in this investigation.PHYSICAL CHEMISTRY LABORATORY,BALLIOL AND TRINITY COLLEGES,OXFORD

ISSN:0368-1645    

DOI:10.1039/CT9109702454

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

HOMOGENEOUS DECOMPOSITION OF OZONE. 2463CCLIV.-The Homogeneous Decosnposition of Ozone inthe Presence of Oxygen and Other Gases.By DAVID LEONARD CHAPMAN and HERBERT EDWIN JONES.IT has been shown by H. E. Clarke and one of us (Trans., 1908,93, 1638) that the rate of decomposition of ozone on the surfaceof glass is so slow that even in moderately small globes the amountof ozone destroyed on t.he internal surface of the vessel may beneglected in comparison with that decomposed in the interior o2464 CHAPMAN AND JONES : HOMOGENEOUS DECOMPOSITION OFthe gas. I n other words, it has been demonstrated that the con-version of ozone into oxygen under suitable conditions may beassumed to be a homogeneous change without any appreciable errorbeing made. It is the only slow chemical change in the gaseousstate which has, as yet, been shown to satisfy the condition ofhomogeneity under re alis ab le conditions .Since the quantitative investigation of a chemical change entirelyconfined to matter in its least complex state might be expected tofurnish results of exceptional theoretical significance, an attemptwas made by Mr.H. E. Clarke and one of us to construct anapparatus with which the velocity of decomposition of ozone in thepresence of oxygen and other gases might be measured; but beforethe apparatus had been sufficiently perfected to furnish satisfactoryresults, Mr. Clarke was unfortunately compelled to relinquish thework. The investigation has been continued by the authors ofthis communication with the aid of a slightly modified and improvedform of the apparatus originally designed by Clarke and one of us.Before giving a detailed account of this apparatus, and the modeof conducting an experiment, it will be convenient to state thegeneral conclusions that have been drawn from the results, and toindicate what we believe to be the theoretical significance of theseconclusions.The results demonstrate that :(a) Oxygen, nitrogen, carbon dioxide, and possibly water vapourhave no effect on the rate of decomposition of ozone, that is, therate of decomposition of ozone in the presence of these gases is afunction of the concentration of the ozone only.( 6 ) Nitrogen peroxide (Andrews) and chlorine accelerate in amarked degree the decomposition of the gas.( c ) I f the order of the change can be represented exactly by anintegral ordinal number, that number is the second.I n respect of their influence on the rate of decomposition of ozone,gases may therefore be separated into two classes-those which arewithout effect, and those which act as powerful catalysts.That aclassification based on such a striking distinction should be possiblelends strong support to the view that the catalytic action of thesecond class is chemical rather than physical in its nature, sincea physical property is generally shared, in a greater or less degree,by all gases. Moreover, nitrogen peroxide and chlorine are sub-stances of which the first is known to react with ozone, and thesecond is closely related to an element, namely, iodine, which hasbeen shown to be oxidised by ozone.The facts, so far as they have been made out, indicate that themechanism of the decomposition of ozone in the absence of catalystOZONE IN THE PRESENCE OF OXYGEN AND OTHER GASES.2465is a sinikle process, consisting of the conversion of two molecuies ofozone during a favourable collision into three molecules of oxygen.Such a view is in harmony with the fact that gases having nochemical action on ozone are without influence on its rate of decom-position (for the number of collisions between pairs of molecules ofozone is almost independent of the diluting gas), and also with thefact that the reaction is of the second order.A result of exceptional interest is that which relates to theFIG. 1.influence of moisture.to the experiment,al section of the paper.The discussion of this will be relegatedEXPERIMENTAL.The apparatus used for the preparation and collection of theozonised oxygen is depicted in Fig.1. The oxygen was preparedby heating potassium permanganate. Dust and carbon dioxidewere removed from it by its being passed through a tube packedwith glass wool and soda-lime. It was stored in a small gas-holderA , which contained concentrated sulphuric acid. The gas-holderwas connected by narrow capillary tubing with a Brodie ozonegenerator B, made of thin glass, as recommended by Shenstone(Trans., 1893, 63, 938). The generator was immersed in dilutesulphuric acid, and its inner tube contained metallic mercury.Itwas connected by capillary tubing with a, vessel C, containing con-centrated sulphuric acid saturated with ozone. As the ozonisedoxygen passed into this vessel, the displaced acid entered th2466 CHAPMAN AND JONES : HOMOGENEOUS DECOMPOSlTION OFreservoir 11. The receptacles 1) and C were connected by a widetube a, in which a tap Tawas inserted, and also by a tube b ofvery fine bore.When T, was closed, the acid entered B very slowly, owing tothe resistance offered to its motion by the capillary tube, and therate at which the ozonised oxygen entered the receiver was cormspondingly-slow. The upper end of D was connected with a deviceby means of which the current of gas could be further regulated.The wide tube E , containing powdered potassium hydroxide, wasground into the mouth d of the receptacle B.E was in turn joinedby rubber tubing to a flask F , containing water, which could besiphoned out drop by drop through the fine capillary t-ube G. Byraising and lowering G, the rate at which the water siphoned overcould be regulated, and the flow of gas through the ozone generatorthereby controlled. The potassium hydroxide in E served todestroy traces of ozone which would otherwise have attacked therubber tube. Before use, the apparatus was cleansed with a hotmixture of potassium chromate and concentrated sulphurie acid,and then with hot distilled water, and thoroughly dried.All air was displaced from the apparatus before starting anexperiment by a, current of oxygen.Oxygen was ,collected in thegas-holder, and a volume of ozonised oxygen sufficient for oneexperiment was prepared from it. The tap Tb was then closed,and the oxygen remaining in the gas-holder A was allowed toescape. The gas in the receiver C was next transferred to theholder A , the taps Ta and Tb being left open. It was then againdrawn slowly through the ozone generator into the receiver C, the.coil being in action. The percentage of ozone was appreciablyincreased by the gas being submitted for a, second time to theaction of the silent discharge.The section of the apparatus used to measure the rate of decom-position of the ozone (at looo) is shown in Fig. 2.The glass tubes, A , and A,, of about 100 C.C. capacity, in whichthe ozone was heated, communicated by capillary tubes, on the oneside with the previously described section of the apparatus, andon the other with the left-hand limbs of the manometers m, and m2,which contained concentrated sulphuric acid.The right-hand limbsof the manometers were connected by capillary tubes and groundglass joints with two bottles, B, and B,, of about 2 litres capacityeach. The corresponding parts of the apparatus were made asnearly alike as possible. The apparatus was connected with aninjector pump at P, and was provided with a mercury manometerat M , as shown in the diagram. Taps TI, T,, and T3, and tapsti, t,, t,, t 4 , t,, $6, t,, t,, and t,, provided with mercury seals, werOZONE I N THE PRESENCE OF OXYGEN AND OTHER GASES. 2467inserted in the positions indicated in the figure.The pressure onthe rightrhand side of the manometers was kept constant by thebottles being immersed in a bath of water at a fixed temperature.The water in the bath was stirred by a current of air, and thetemperature was controlled by a delicate electric thermoregulator.During an experiment the tubes A , and A , were kept at loooby means of a current of steam, which entered the jackets sur-rounding them from above. I n it preliminary experiment, it wasshown that the temperature of both of the tubes could be raisedto that of the steam in the same time. Before the experimentsJ twere started, ozonised oxygen was passed through the heated tubesfor several hours.Znfluence of Oxygen on the Rate of Decomposition of Ozone.‘The object of the first series of experiments was to ascertain theeffect, if any, of varying concentrations of oxygen on the rate ofdecomposition of the ozone.The method of conducting an experi-ment was as follows.A quantity of ozonised oxygen sufficient for one experiment wascollected in C, the ozone remaining in the generator and capillarytubes being subsequently driven out through the taps T, and T, bya stream of oxygen from the holder A .With the taps t,, t,, and T, closed, and t,, t,, t,, t,, t,, t,, and t,open, the apparatus was exhausted as completely as possible by theinjector pump. The taps t,, t,, and t , were then closed, and oxyge2488 CHAPMAN AND JONES : HOMOGENEOUS DECOMPOSITION OFadmitted from the holder A through t, and t , until the volumebetween the taps t , and t , and between the taps t , and t, had beenfilled.The pump was again set in action, and the taps t,, t,, andt , cautiously opened. When the limit of exhaustion attainablewith the injector pump had been reached, the process describedabove was repeated, the removal of traces of air from the tubesA , and A , being thereby ensured.Bycautiously opening t , and t,, ozonised oxygen was admitted to thetubes A , and A , from the receiver C, the pressure on both sidesof the manometer being maintained the sanie by the simultaneousadmission of air into the bottles B, and B, through the taps t , andT,. When the manometer M indicated a pressure of a little lessthan half an atmosphere, t , was closed.The ozone left in thecapillary tubes on the left-hand side of the taps t, and t , was dis-placed by oxygen, and oxygen was then introduced into the tubeA , by carefully opening the tap t,, air being at the same timeadmitted through t,. The taps t, and t , were closed when themanometer m indicated a pressure slightly less than an atmosphere.The tube A , was thus filled with ozonised oxygen at the pressureof half an atmosphere, whilst A , contained the same amount ofozone, but approximately twice as much oxygen.The tubes having been filled, the taps t, and $8 were opened,and a rapid current of steam wm passed through the steam jackets.After one an& &half minutes (when the contents of the tubes hadattained the temperature of the steam), the taps t , and t 8 wereclosed.The differences of pressure registered by the manometerswere noted a t regular intervals. Curves were plotted, showing therelation between the increase of pressure in the tubes A , and A ,and the time. It sometimes happened that the total amounts ofozone contained in A , and A , respectively (as indicated by the totalchange of pressure) were not exactly equal. In such cases a simplecorrection was applied in order that the results might be strictlyconip ar ab le.The changes of pressure in cm. of sulphuric acid are plottedagainst the times, and the four pairs of curves thus obtained areshown in Fig. 3. The circles correspond to the changes ofpressure in the tube which contained ozonised oxygen at apressure of half an atmosphere, and the crosses to changes ofpressure in the other tube which contained the same amount ofozone per unit volume, but twice as much oxygen.The numbersattached to the curves indicate the order in which the experimentswere performed.These results point decisively to the conclusion that variation inAfter the final exhaustion the taps t,, t,, and t , were closedOZONE IN THE PRESENCE OF OXYGEN AND OTHER GASES. 2469the pressure of the oxygen mixed with ozone is unattended byappreciable alteration in the velocity of decomposition of the lattergas at looo. This conclusion does not appear to agree with theobservations of previous investigators.S. Jahn (Zeitsch. amrg. Chem., 1906, 48, 260) and Perman andFro.3.7 I -I I___I____ t-- -- 1 1-ripTime : 1 division=+ hour.Greaves (Proc. Roy. Soc., 1908, A , 80, 353) assert that the rate ofdecomposition of ozone varies approximately inversely as the oxygen-pressure. If the reaction were reversible, this result might beexpected; but Perman and Greaves and others have conclusivelydemonstrated that at looo it may be regarded as irreversible.".Ic Fisher and Braehmer (Ber., 1906, 39, 940), have recently shown that ozone isformed in srnall quantities from oxygen a t teinperatures above 1300".VOL. XCVII. 7 2470 CHBPMAN AND JONES : HOMOGENEOUS DECOMPOSITION OFI n order to explain his results, Jahn has suggested that the decom-position of ozone occurs in two stages, expressible by the equations :o,=o,+o .. s . . . . . ( a )0,+0=20, . . . 4 . . . . ( 6 )the first stage being rapid and reversible, whilst the second is slow.These assumptions would require that the rate of decomposition ofthe ozone should be directly proportional to the square of theconcentration of the ozone, and inversely proportional to the con-centration of the oxygen. Jahn’s experiments were carried out at127O, at which temperature the reaction is bimolecular, accordingto Waxburg (Sitzungsber. R. Akad. Wiss. B e r l i n , 1901, 48, 1126).Perman and Greaves, on the other hand, consider that Jahn’shypothesis is not justifiable, and that the alleged effect of theoxygen is due to variations in the gas film on the glass surfaceresulting from the changes in the oxygen-pressure.If, however,the decomposition occurs mainly in the body of the gas, as appearsfrom the work of Clarke and one of us (Zoc. cit.), the suggest.ionmust for that reason alone be discarded,Imfluence of Aqueous Vapour om the Rate of Decomposition ofOzone.A second series of experiments was performed in order toinvestigate the influence of water vapour on the rate of decom-position of the gm-a subject of considerable interest, both onaccount of the diversity of the .results obtained by previous workersand of its bearing on the general problem of the catalytic effect ofmoisture on most simple chemical changes.The experiments were carried out as described above, except tha’tboth tubes were filIed with ozonised oxygen at a pressure of a littleless than an atmosphere, and that the gas which entered the tubeA , was saturated with water vapour by its being passed througha small wash-bottle containing distilled water.To prevent anymoisture being carried over into A,, a tap was inserted on the left-hand side of the wash-bottle, which was shut off while A , was beingfilled.The eight curves obtained by plotting the results of four experi-ments are shown in Fig. 4. Ir? experiments IIIa and IVa, themoist gas was contained in the tube which held the dry gas in thetwo previous experiments. The crosses correspond to the changesof pressure of the moist gas, and the circles to the changes ofpressure of the gas dried by concentrated sulphuric acid.Andrews and Tait, and also Brodie, in their classical memoirs oOZONE IN THE PRESENCE OF OXYGEN AND OTHER GASES.2471ozone, recommend the use of carefully dried oxygen for the pre-paration of Ozone by the silent discharge.Shenstone and Cundall (Trans., 1887, 51, 610) showed thatcarefully dried oxygen can be easily converted into ozone-a factwhich was shortly afterwards confirmed by Baker (Trans., 1894,65, 611), who stated that ‘‘ ozone was formed as rapidly in oxygendried with phosphorus pentoxide as it was in the same tube whenthe oxygen had been dried only by sulphuric acid.”As a result of further investigations, Shenstone (Trans., 1897,71, 471) drew the remarkable conclusion that all previous stateFIG. 4.ments on the subject were wrong. He observed that a high per-centage of ozone is formed by the action of the silent discharge onoxygen saturated with water vapour, aad that the ozone thusproduced is remarkably stable.On partly drying the gas, thepercentage of ozone produced was considerably reduced, and thegas was found to be singularly unstable. Oxygen which had beenthoroughly dried was found to become ozonised exceedingly badly.Subsequent investigations have failed to confirm Shenstone’s work,and Armstrong has suggested that his anomalous results may be dueto the presence of oxides of nitrogen (formed by continuous action of7 u 2472 CHAPMAN AND JONES : HOMOQENEOUS DECOMPOSlTION OFthe discharge from traces of nitrogen contained in the oxygen),which, as Andrews has shown, immediately destroy ozone.Thomson and Threlfall (Proc.Roy. SOC., 1885, 40, 340) assertthat ozone is produced when an electric spark is passed throughvery carefully dried oxygen.Warburg (loc. cit.) maintains that at looo the dry gas is justas stable as the moist.Warburg and Leithauser ( A n n . Physik, 1906, [iv], 20, 751)have, moreover, shown that the formation of ozone both in oxygenand in air is retarded by the presence of moisture, the retardationbeing greater in oxygen than in air.Fischer and Marx (Ber., 1906, 29, 3631), working d t h a Nernstfilament, find that the first traces of moisture lessen the yield ofozone by catalytic action, whereas larger quantities of water vapourincrease the yield of hydrogen peroxide at the expense of the ozone.Perman and Greaves (Zoc.cit.) claim to have shown that watervapour accelerates the decomposition of ozone, and that the effectis roughly proportional to the amount of water vapour present.They consider that the effect is due to the deposition of moisture onthe surface of the glass, which causes the ozone to be more rapidlycondensed. They point out that their results do not agree withthose of Shenstone.Although in our experiments the Oaone mixed with a considerableproportion of water vapour appears to decompose at a slightlygreater rate than that which has been dried with sulphuric acid,the difference is so small that we are disposed to think that it oughtto be attributed to the gradual removal of water vapour, adsorbedon the inner surface of the glass, at the higher temperature, or tosome similar cause.We are, at least, justified in concluding thatat 1000 a large difference in tho quantity of water vapour presentwith the ozone is not accompanied by any marked change in thevelocity of decomposition. Our results agree with those ofWarburg, whose experiments were also conducted at looo.Influence of Nitrogen, Carbon Dioxide, Carbon Monoxide, andChlorine o n the Rate of Decompaitwn of Ozone.The negative character of the results obtained with the first threegases is sufficient proof that no appreciable quantity of impuritycapable of destroying the ozone was contained in them. I n eachcase concentrated sulphuric acid was used to dry the gas. Theexperiments were conducted as follows.A tube containing soda-lime was introduced between the gas-holder and the ozone generator in order to remove any carbondioxide from the oxygen.The tubes A , and A , were filled witOZONE IN TRE PRESENCE OF OXYGEN AND OTHER GASES. 2473ozonised oxygen at a pressure of half an atmosphere in the mannerpreviously described. Oxygen was then admitted to one tube untila pressure slightly less than an atmosphere was registered by themanometer. The gas of which the effect was being investigatedwas then introduced into the other tube through T, or T, until thepressure in both tubes was the same. The rates of decompositionof the ozone in the two tubes were compared. Several experimentswere performed, the gas under investigation being introduced intoA , and A , alternately.r-r-I-r * FIG.5.T h e : 1 division = 0.5 hour.I n the case of nitrogen, no effect on the velocity of decompositionwas observed, while the experiments with carbon dioxide and carbonmonoxide demonstrate that the influence, if any, of these gases issmall. Chlorine, on the other hand, was found to decompose ozoneso rapidly that it was quite impossible to make any trustworthymeasurement of the velocity of decomposition.The six curves obtained by plotting the resulbs of three experi-ments with nitrogen are shown in Fig. 5. I n the experiments I1and 111, the nitrogen was contained in the tabe which in theprevious experiment held ozonised oxygen only. The crosse2474 CHAPMAN AND JONES ; HOMOGENEOUS DECOMPOSITION OFcorrespond t o changes of pressure in the gas which containednitrogen, and the circles t.o the changes of pressure in the othertube.The readings taken in the experiments with carbon dioxide I andcarbon monoxide I1 are plotted in the curves shown in Fig. 6.Thecircles correspond to changes of pressure in the tube whichcontained the ozonised oxygen only.FIG. 6.Time : 1 dkision=O*5 hour.Shenstone and Evans (Trans., 1898, 73, 246), while investigatingthe influence of the silent discharge on atmospheric air, weresurprised to find that much as 98 per cent. of the oxygencontained in the air could be converted into ozone, the maximiuliyield of ozone obtained from pure oxygeii under the sa.me con-ditions being only 13.6 per cent. A similar observation was madeby Brodie (Phil. Trans., 1874, 164, 101) when he submitted carboOZONE IN "HE PRESENCE OF OXYGEN AND OTHER GASES.2475dioxide to the action of the same agency; the carbon dioxide wasdecomposed into carbon monoxide and oxygen, 85 per cent. of theoxygen being in the form of ozone. It was conceivable that theseinteresting and peculiar phenomena might arise from inhibitiveeffects on the thermal decomposition of ozone of nitrogen and carbondioxide respectively. The above experiments demonstrate that suchan explanation is untenable, and that the phenomena in questionmust be due to some obscure influence of the nitrogen on the onehand, and the carbon dioxide or carbonmonoxide on the other, onthe energy of the discharge itself.Observations on the Order of the Change.In examining our results with a view to det'ermining the orderof the change, we have adopted a novel method.Instead ofcalculating the value of the constant for each observation on theassumption that the change is of a given order, we compare theamounts of ozone decomposed at given intervals of time with thosecalculated for changes of a specified order. This method ofexamining the results has the obvious advantage of enabling us t odecide at a glance whether the departure of the experimentalnumbers from those calculated from any given set of assumptionsas to the nature of the change lie within the limits of experimentalerror.A curve of a given order is drawn through three points on theexperimental curves, the points selected being the origin, and thepoints corresponding with the last observation, and am observationmade when about half of the ozone was decomposed.The differencebetween the magnitudes of ordinates (amounts of ozone) of theexperimental and calculated curve at different times are thentabulated. In the present case it was only necessary to comparethe experimental curve with calculated curves drawn through itof the first and second order. It will be seen from the numbersgiven that the reaction is very nearly of the second order. Onlythe numbers obtained in those experiments in which large quantitiesof dry ozone were decomposed, and in which readings were takenfor a considerable period of time are submitted to examinationbelow2476 HOMOGENEOUS DECOMPOSITION OF OZONE.Examination of the Measurements Made in Experiment I V a .(Al.)Time.2510165897178238298397508CalculatedObserved change ofchange of pressure, Difference :pressure. 1st order. k, = 0'00648.0.60 0 -36 -I- 0 '241 -30 0'91 +0-391 *go 1 -68 +0'222.95 2.57 4- 0.387.00 7-00 08 *50 9 '26 + 0.7110.30 11-26 +0'9610.95 11.76 t o 3 111-40 11-97 + 0.5711.85 12.08 + 0-2312'10 12.10 0Sum of difTerences= + 4.51Obs-rvedchange ofpressure.0.601-301 -902 -957-008.5010.3010.9511-4011 -8512'10SumCalculatedchange ofpressure, Differcnce :2nd order. k2=0'00142.0 -48 + 0'121-16 + 0.142-13 - 0'233-11 - 0.167.00 08-65 + 0.10l O - O i - 0.2310.93 - 0'0211'34 - 0.0611.78 - 0.0712.10 0of differences = - 0.51The calculated curves are drawn through the origin, the point(58, 7*00), and the point (508, 12.10).If the difference betweenthe ordinates of the calculated and experimental curves indicatesthat the order of the reaction is of a higher value than thatcorresponding with the calculated curve, a plus sign is attached toit, a minus sign having the reverse significance.It will be evident on inspection of the above numbers that thereaction differs but slightly from one of t,he second order.Examination of the Measurements made in Experiment IZZa.closeIy to a reaction of the second order.(Al.)I n this experiment the rate of change approximates still moreTime.136912182430516075105129156276381489531CalculatedObserved change ofchange of pressure, Difference :pressure. 1st order. k, = 0-00624.0.25 0.17 + 0.080-75 0-50 + 0'251 -55 0 -95 f 0.601.95 1'44 + 0.512-40 1 '88 t-0'523'15 2.69 +0'463-85 3-26 -i- 0.594 *50 4.15 -t 0.356-10 6-16 - 0'066-85 6 3 5 0 .oo7-50 7-82 f - 0 - 3 28.60 9 '24 + O 649-15 10.00 + 0.859-75 10*60 +0%511'40 11.81 + 0'4111.80 11 -85 + 0'0511.85 11.85 0 .ooSum of differences = +7.0611 .oo 11 -63 -t 0'63CalculatedObserved change ofchange of pressure, Difference :pressure. 2nd order. k2= 0~00141.0-25 0 '23 +0'020.75 0-69 +0-061.55 1 -30 + 0'251.95 1.86 -k 0.092'40 2.36 -t 0.043'15 3 '25 - 0-103.85 4'00 - 0.1 54'50 4 '64 - 0'146'10 6.35 - 0.256.85 6 -85 0 .oo7.50 7'60 t-o.108 60 8'61 + 0.019-15 9'19 + 0'049.75 9 '69 - 0.0611 .oo 10.92 - 0'0811'40 11.43 + 0'0311 -80 11'76 - 0 '0411.85 11 -55 0.00Sum of differences = - 0-1METHYL-ORANGE AND METHYL-RED. 2477I n the other experiments, in which the initial percentage of ozonewas less, or the period during which observations were madeshorter, the order of the change falls to a greater extent below thesecond. All the experiments are conclusive in demonstrating,however, that if the order of the change can be represented by anintegral ordinal number, that number is the second.SIR LFNLIXE JENKINS LABORATORIES,JESUS COLLEGE, OSFORD

ISSN:0368-1645    

DOI:10.1039/CT9109702463

出版商:RSC    

年代:1910

数据来源: RSC