摘要:

Issued 9/ 121 1892. PROCEEDINGS OF THE CHEMICAL SOCIETY. No.116. Session 1892-93. December 1, 1892. Professor A. Crum Brown, F.R.S., President, in tohe Chair. Drs. William J. McKerrow, John Shields, James Walker and W. P. Wynne were formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. John Edwin Brockbank, The Croft, Kirksnnton, ui& Carnforth ; Ed-ward Brooke, West Court, Chalk, Gravesend, Kent ; Charles Dreyfus, Ph.D., Clayton Aniline Co., Clayton, Manchester ; James Elias, Briton Ferry, Glamorganshire ; Alexander Stanley Elmore, Twaite Gate, Leeds; George Neville Huntly, 56, Sheen Road, Richmond, Surrey; Charles M. Luxniore, B.Sc., 529, Battersea Park Xoad; R80bert Henry Owen, Pas-y-coed, Troedyrhiw, near Merthyr Tidfil ; John William Towers, Brantwood, Allerton, near Liverpool ; William Ji:rnest Wheeler, Cumberland House, Meynell Road, South Hackney.Of the following papers those marked * were read :-*70. " The isolation of two predicted hydrates of nitric acid." By S. U. Pickering. In the case of nitric acid the curves plotted from both Berthelot's and Thomsen's heat of dissolution values were found to exhibit a well-marked " break " at the composition of the trihydrats ;Kolb's density values afforded a similar indication, and also exhibited a "break " at the ?noprohydrate ; on masking a series of freezing point determinations, both these hydrates, but no others, were isolated in the crystalline condition. The melting point of the trihydrate is -18.2" and that of the monohydrate -36.8".In the case of each the melting point is lowered by the addition of either acid or water. 186 These results are regarded by the author as an important confirm-ation of the views expressed by him in pi-erious papers. 71.* "Anhydrous oxalic acid." By W. W. Fisher, M.A. Although the crystallised dihydrated acid is a familiar substance, anhydrous oxalic acid is but little known, except as a roughly dried mass, probably because it so readily attracts moisture. E. Seichert has shown that it is obtained from the hydrate by treatment with coii- centrated sulphuric acid (Jena. Zeit., 1864, vol. 1,p. 244), but he states that the excess crystallising from a heated mixture of the two substances is a hydrate-this, however, appears to be an error.A. Villiers, in 1880 (Compt. rend., 90, 82l), published a note on the crys- tals obtained by this method, and pointed out that they were of greater relative density tban sulphuric acid. The crystalline form of the anhydrous acid has been described and figured by Loschmidt (Wien. Akad. Ber., 1865), but owing to the readiness with which the crystals change in air, the determinations were but approximate ; they are prismatic octahedra, resembling elongated crystals of alum. The best method of producing the crystals is to allow ordinary hydrated oxalic acid to remain in contact with concentrated sulphuric acid for a few months ; if the two substances are sealed up together in a glass tube, beautiful specimens may be obtained.Oxalic acid, whether hydrated or not, is sparingly soluble in sulphuric acid, about 3 per cent. being taken up by the cold liquid. The anhydrous acid dissolves with a slight fall of temperature, while a rise of temperature is not,iced when the hydrated crystals dissolve. Dissolution takes place readily on warming, and part of the dissolved acid separates in the anhydrous state on cooling the solution, a supersaturated liquid being obtained from which the excess is slowly deposited. The relative density of the crystals, determined in dry petr- oleum, was found to be 1.878 compared with water at 4",while the density of the hydrated acid similarly determined was found to be 1.608 (Bodeker, Jahresb., 1860, 17, gives d = 2.0).This difference affords a ready means of distinguishing the hydrated crystals, as when placed in concentrated sulphuric acid they at first float, but losing their transparency and turning white as they become de- hydrated, they increase in density and finally sink to the bottom. The limit of concentration at which crystallised oxalic acid in con-tact with sulphuric acid retains its water is between 60 and 70 per cent. at ordinary temperatures, as the hydrated form is unchanged in the wcaker acid and the anhydrous crystals are permanent in the 70 per cent. sulphuric acid. Hydrated oxalic acid behaves in a similar manner towards nitric acid, as it may be recrystallised from that containing about 70 187 per cent.of real acid (d = 1.2) without losing its water, while in a highly-concentrated acid (d = 1-50)it is dehydrated. The crystals deposited from nitric acid are usually less brilliant in appearance and smaller than Chose formed in sulphuric acid. Commonly, oxalic acid is dried by the rough method of heating in an open dish, when a considerable part of the water is expelled, but ninch loss takes place by volatilisation, and unless the acid be actually sublimed the dr-ying is still imperfect. It can, how-ever, be easily and completely dried in a vacuum by means of the arrangement described by McLeod (0.X.Traws., 1883,384) or in an ordinary retort ; for this purpose, the retort containing the acid is attached to a receiver containing strong sulphuric acid, exhausted by a water vacuum-pump, and heated at 60” on a water-bath; in a few hours the theoretical quantity of water is expelled from the crystals.A specimen dried in tbis manner, which had been transferred to a tube, then sublimed in a vacuum by a steam heat and sealed up in the year 1890, appeared in the ordinary form of the sublimed acid as a mass of needles, but after a few months, by slow resublimation at ordinary temperatures, the interior of the tube became coated with brilliant crystals resembling those deposited f rom sulphuric acid. The volatility of hydrated oxalic acid was observed by Faraday {Journal Roya,l Institution, 1830), who found that when kept in an open tube for four years within a stoppered bottle containing calcium chloride, some oxalic acid passed over into the calcium solution, and new crystals were visible on the surface of the old ones.The hydrated acid does not appear to sublime as readily as the anhydrous form, specimens enclosed in vacnous tubes showing, after several months, hardly any signs of volatility. The stability of oxalic asid is evidenced by the fact that it can be readily sublimed in a vacuum at temperatures up to 150”;and that, even if heated on the water-bath in concentrated sulphuric acid, a portion will sublime from the liquid undecomposed. Anhydrous oxalic acid will dissolve in warm ethylic oxalate or glacial acetic acid, but does not cryatallise well from either solvent, only a powdery product being obtained.X72. “The production of orcinol and other condensation products from dehydrscetic ‘acid.’ ” By N. Collie, Ph.D., and W. S. Myers, B.Sc. Oppenheim and Precht have stated (Bey., 1876, 324) that orcinol is formed when dehydracetic “acid” is hydrolysed by means of barium hydrate, but they obtained only a very small quantity, and based their conclusion on qualitative evidence ; their observation is 188 now corroborated by the authors, who have obtained orcinol, not only from dehydracetic "acid " and dimethylpyrone by t'he action of barium hydrate, but also by boiling B mixture of syrupy caustic soda and dehydracetic " acid ; )' in the latter case, a true (carboxylic) acid is first produced, which loses carbon dioxide, leaving orcinol.Among the products obtained on submitting diacetylacetone to the action of barium hydrate, the authors have discovered a substance crystallising in bright yellow needles melting at 180-181", which is probably a naphthalene derivative, its formation involving the change expressed in the equation 2C,H,,,03 = CllHIPOS+ 3H,O. Mention is also made of a substance exhibiting a magnificent bZue Jluorescence formed in the preparation of diacetylacetone from di-methylpyrone by treatment with baryta water. An amidodehydracetic " acid )' is described, which is formed by the interaction of solid dehydracetic " acid " and the strongest ammonia, solution ; it crystallises in long silky needles, m. p- 192-196", and is readily reconverted int,o dehydracetic " acid " by alkaline or acid hydrolysis.*73. " Observations 011 the origin of colour and on fluorescence." By W. N. Hartley, F.R.S. Adverting to the arguments used by Armstrong in these ' Proceed-ings ' (1888, 4, 27) the author defines colour and the cause of colour, the nature of visible and invisible colour, and the linlits of visibility in *the spectlrum from a physical standpoint. It is contended that, it cannot be stated in general terms that colour is due to special modes of atomic arrangement, but that the statement may be applied in a restricted sense to certain carbon compounds, especially to thost, included in the class to which organic dye-stuffs belong ; azd it is pointed out that' all open chain hydrocarbons exert a coiitinuous ctbso~p-tion the extent of which depends on the number of carbon atoms in the molecule.Attention having been drawn by Armstrong to the condition of st,rain and of instability existing in many coloured substances, it is pointed out that this is owing to their being all endothermic com- pounds ; that ethylene, acetylene and benzene are endothermic, but that derivatives of the last-named only are coloured ; and finally that all organic colouring matters are endothwmic compounds. This is considered to be the physical cause of that which Armstrong has not defined but which he terms " reactivity " or " high potential." It is next shown that anthracene is not colourless but has a true greenish-yellow colour in addition to its fluorescence.The results of a number of experiments on fluorescence are then given in detail, and from these the following conclusions are drawn :- 189 1, Quinine dissolved in alcohol exhibits a beautiful, bright; violet fluorescence. 2. Cblorhydric acid is not fluorescent. 3. Quinine hydrochloride is very feebly fluorescent, but without distinct colour. 4. Chlcroform is feebly fluorescent, but without distinct colour. 5. Both chlorhydric acid and chloroform can extinguish those rays which are the cause of the fluorescence in quinine. 6. Some alkaloids may be recognised by the degree and colour of the fluorescence they exhibit. 7. Normal alcohols of the ethylic series are fluorescent ; so, also, are the fatty acids.8.Glycerol has a violet fluorescence. 9. Benzene has a pale blue fluorescence, azobenzene a greenish-blue. 10. Rock crystal has a pale bluish-violet fluorescence, flint glass a strong blue, and crown glass a very brilliant and beautiful blue fluorescence. 11. Substances which are nct fluorescent in strong solntions may become so on dilution, particularly if they exert a very power- f ul absorption of the ultra-violet or visible spectrum. The colour and fluorescence of ant’nracene are explained. Finally, the case of ortho- and para-nitrophenol and of meta- and para-nitr- aniline are discussed and it, is conteiided that the forrnub of ortho-nitrophenol and metanitraniline should not at present undergo modi- ficat ion.74.“ The origin of colour. V. Coloured hydrocarbons and fluor- escence: a reply to Professor Hartley’s observations on the origin of colour and of fluorescence.” By Henry E. Armstrong. A perusal of my friend’s objections leaves me under the impression that he scarcely apprehends my views on the origin of colour, and that he does not fully comprehend my aim; but this is not SUP prising, my arguments having hitherto been published in the briefest and most condensed form, as I have always felt that, in dealing with so difficult and extensive a subject, it was necessary to proceed slowly, and to read, mark, learn and give much time for inward digestion and further experimental study before venturing to discuss in detail the manifold issues involved.My critic having clearly accentuated many of the points which demand consideration, I am in consequence much indebted to him; moreover the fact that he has paid special attention to tbe study of ultra-violet absorption 190 spectra lends great weight to his statements, which serve also to indicate the departure from current views involved in the adoption of the hypothesis of which I am an advocate. I have never left out of account the fact that, in a physical sense, all substances are colonred-all substances possessing the power of absorbing the light waves, either generally or selectively in some part either of the visible or invisible spectrum. My contention has been simply that, confining our attention to visibly coloured organic substances, to substances coloured in the ordinftry conventional sense, it is a most remarkable fact that in those cases in which the “constitution ” of the coloured substance is fairly well established, coloured substances are all of one type; and from this base I have started on the enquiry whether all coloured organic compouiids are not similar in type.According to Hartley, “ in order to study the origin of colour, we must first consider the case of colour in those molecules which are of the simplest possible constitution, such as, for instance, the molecules of chlorine, oxygen, ozone and water.” Undoubtedly this would be the case if we knew their “ constitution ;” but we do not, our knowledge being confined to the fact that their molecules consist, of a certain number of atoms-which is insufficient.He also asserts that “the colour or effect on light caused by molecules of oxygen, ozone and water is in no way different from that caused by molecules of aniline blue.” ThiR ma,y or may not be a correct inter- pretation of the facts ; apparently the molecules of both oxygen and ozone are intrinsically coloured, but is tlis water molecule? It is an impsrtant question for experimental investigation whether water in a perfectly gaseous state would be blue when viewed in a column of sufficient thickness ; its colour may originate in the poly-molccules which presumably are contained iu the liquid. My critic furthermore states that “ all organic colouring matters arc endothermic compounds.” This may well be the case, but the con- verse does not hold, as he himself recognises, and the conclusion helps us but little ; such a phrase, in fact, serves but to obscure the issue by merging the less in the greater.A most important section of the paper under notice is that relating to fluorescence, describing a series of observations which lead their author to conclude that many substances are fluorescent which hitherto have not been considered to be so, e.g., alcohol and its homo-lopes, &c. There can be no question as to the accuracy of these observations, but until many of the substances have been Further studied, and every possible precaution has been taken to obtain thein pure, I must, with all deference, decline to accept all the results as final. In the case of naphthalene derivatives, especially the naphthyl- 191 amine- and naphthol-sulphonic acids, with which I am somewhat.familiar, intensely fluorescent solutions are the rule-yet, I very much doubt their being fluorescent, having noticed, time after time, that the more nearly pure the substance becomes, the less fluorescent it is. It is easy also to account for the presence of fluorescent impurities in these cases on the assumption that during the heating with sulphuric acid oxidation takes place, and that the resulting phthalic acid, or nearly allied compound, condenses, forming a fluorescein ; a strong argument in favour of this explanation is afforded by the fact that the disnlphonic acids which ape formed with the aid of fuming acid at somewhat elevated temperatures, aid are very soluble, and there- fore difficult to purify, are far more strongly fluorescent than the monosulphonic acids, which are difficultly soluble and comparatively easily purified.In considering the "origin of fluorescence " and in regarding it as the " beginning of colour," I am, undoubtedly, entering into a highly speculative region ; yet the facts aye very striking. A single example will suffice. Aiithracene is intensely fluorescent, and it may be repre- sented by a quinonoid formula ; the isomeric hydrocarbon, phen- anthrene, however, which cannot be so represented is colourless and non-fluorescent,, according to present knowledge.Hartlefs dis-C0vei-y that an thracene has a visible slight, greenish-yellow colour is to ine one of extreme interest, and 1cannot refrain from referring to it as a very strong confirmation of my hypothesis. Furthermore, while an intense, yellow colour is produced by " weighting " what may be termed, for convenience, the '' quinonoid radicles " of anthra-cene by introducing chlorine or bromine in place of the central hydrogen atsoms, no such effect follows the introduction in a similar manner of bromine into phenanthrene, dibromophenanthrene being colourless like the hydrocarbon. And yet anthraquinone and phen- anthraquinone are both coloured, the latter being deep orange and the former yellow. A/\/\ /\/\ABr i.i PI IcI i I lcl I 1 \/\ ($1..VV\Y \/'$\/ I i/ \"Bl-i.i'Antliracene.Dibromanthracene. \/ \/Phenanthreiie. Dibromophen-anthrene. Much more evidence of this character might be adduced, but 1 have said sufficient to show why Hartley's arguments have not shaken my conviction that we may eventually be led to regard fluorescence 192 as a feeble manifestation of that which we ordinarily describe as colour. While speaking of anthraceno as a coloured hydrocarbon, reference may be made to other coloured hydrocarbons, of which we now know several, vie., carotin, and the red hydrocarbon, C26H16, obtained br van Dorp and de la Harpe by passing fluorene over heated lead oxide, which has recently been reinvestigated by Graebe (Bey., 1892, 3146). We know nothing of carotin at present.Graebe represents the hydrocarbon from flnorene by the formula 76H4>CZC<~H4y6c, C,Ha 46 and therefore terms it dibiphenylenethene ; I venture to suggest that it would be more appropriately named Erythrophene, a term which does not commit us to any definite view as to its constitution. I have no hesitation in asserting that a hydrocarbon represented by the forniula, proposed by Graebe would be colourless, and I would suggest tlhe formula given below as more probable; at the same time, it may be pointed out that the yeZZow hydrocarbon C2,H14(xanthopherte) which van Dorp and de la Harpe obtained together with " erythrophene " may be a diphenylenated anthraceue. /\iiY'c\/ \/\II I! \/ //\/Hc\/\ \/Erythroph ene.Xanthophene. Both hydrocarbons are represented by quinonoid formula and the '' quinonoid radicles " are heavily "weighted " ; hence they are somewhat intensely coloured. As to the nitrophenols, I have not called in question the constitu- tion of the ortho-compound simply because it has a yellow colour: I have also pointed out that it differs in many other respects in a marked manner from its isomerides. Hartley's remarks appear to me in no way to affect my argument. With reference to the nitro-com- pounds, he states that " a very little shifting of the region of absorp-tion to rays a little more or a little less refrangible makes such substances colourless or coloured." No doubt this is so, but tdlie question I would raise is whether the shifting necessary for the pro- duction of visible colour (and in a measure of fluorescence) is not conditioned by a special character of structure. In such a case as 193 that of diorthonitrophenol, for example, which is yellow and affords intensely red metallic derivatives, yet yields colourless ethers, it is very difficult to avoid the conclusion that this is so: if we consider the propyl and potassium derivatives, the change from colour to colourlessness, or vice vers&, cannot be conditioned by a change in “ weight ’’ of the radicles, as they are so nearly alike in this respect ; Hartley, I imagine, would attribute the difference to the higher “ energy ” of the metallic radicle, but this latter idea is also, in a measure, included in my suggestion that colour in such a case is developed as a consequence of an isodynamic change, and it must not be forgotten that the evidence of changes of this character occurring is rapidly increasing in volume, e.g., Perkin’s recent observations on the magnetic rotation of compounds supposed to contain acetyl.Hartley ’s explanation of the non-fluorescence of quinine hydro-chloride-that it is due to the absorption by the hydrogen chloride solution of the very rays which are the cause of the fluorescence in quinine-is both simple and satisfactory, and I have no hesitation in accepting it; but this in no way alters my conviction that the fluor- escence of quinine itself is in all probability conditioned by pecu- liarity of structure. Finally, I do not understand why “analogy ” should lead us to expect hydrogen chloride to be coloured because chloririe is, or nitric acid to be coloured because NO, is ; in such cases, we have, I think, at present no reason to expect analogous behaviour, nor indeed any information at our disposal from which coiiclusions can with justice be drawn.In the discussion on a previous occasion (these Proceedings, 1892, lOS), I said that it appeared probable t,o me that ultimately colour would be traced to that peculiar condition represented couventionally by a double bond, the atoms being regarded as altogether subordinate. It is perhaps desirable that J should now more fully explain my views as to the manner in which the “ quinonoid mechanism ” conditions colour.Briefly, I would suggest that in yuinonoid compounds there are two “colour ce~~zt~es,”corresponding to and expressed by the symbol n -in formulae such as I have used in representing coloured substances. These centres, I imagine, co-operate in producing colour through interaction of the light-waves which have traversed them. Sub-stances in which there are no such co-operating centres may absorb generally or selectively in “nltra ” and “infra ” regions of the spectrum, but without exhibiting “visible colour.” In this manner, it is possible, I think, to account for the appearance of colour in sub- stances like diacetyl, Me*CO*CO*Me, and dibenzoyl, Ph-CO-CO-Ph, in which there are two contiguous CZO groups--i.e., which possess a pseudo-orthoquinonoid structure without being quinones.The colour centres may be likened to elastic gratings, in order to represent the modifications induced by attaching different radicles ; in order to account for variation in shade of colour, such elastic ptings may be pictured as undergoing “ longitudinal ” and “lateral ” deQormations, varying in extent and character according as the ‘‘ weight *’ and character of the attached radicles is varied, and as capable, therefore, of differently affecting the incident rays. How-ever incorrect, from a physical standpoint, this imagery may appear, I trust it will suffice to make my meaning clear. It is not inconceivable that the distinction which I have sought to make between visible colour and physical colour is no arbitrary one, but is inherent in the human optic mechanism ; that our perception of colour, in fact, is itself conditioned by, and exerted through, the agency of quinonoid matters.The discussion of the origin of colour from this point of view appears, therefore, to be of importance to physiologists, as well as to chemists and physicists. “75. “The origin of colour. VI. Azobenzene.” By Henry E. Armstrong. A compound represented by the formula C6H5*N:N*C6H5obviously does iiot come within my “colour rule,” and should, in fact, be colourless : yet azobenzene is a brilliantly orange-red coloured sub-stance ; moreover, the formulae usually attributed to the diazo-salts- e.g., diazobenzenc chloride, CsH,*N:NICl-represent these as compar- able in constitution with azobenzene, yet they are colourless: hence I have long doubted the correctness of the formula attributed to azo-benzene. Werigo, in a paper, “Ueber die Additionsfahigkeit des Azo-benzids” (Annalen, 1872, 165, l89), has drawn attention to the readiness with which azobenzene forms addition compounds, and describes a hexabromide; he also states that it affords a colourless tetrabromo-substitution derirative.At my request, Mr. E, Mills has undertaken to revise Werigo’s observations and to study the bromo- and other derivatives of azobenzene in detail, as these promise to be of considerable interest. It appearsd not improbable that Werigo’s hexabromide belonged to the diazo-perbromide class, but this, it seems, is not the case ; by treating it with ammonia, Mr.Mills has obtained only bromo-sub- stitjution derivatives of’ azobenzene-chiefly diparabromazobenzene--no uzoimide being formed (cf. Meldola and Hawkins, t,hese Proceed- ings, 1892, 133). He has confirmed Werigo’s statement that when bromine acts on a Lot alcoholic solution of azobenzene, a colozcrless tetr~ibromo-derivative is produced, which, on reduction, yields a tetra- 195 bromobenzidine apparently identical with that prepared from benz- idine by Claus and Risler ; and as he has not succeeded in obtainiug the colourlees tetrabromo-compound from diparabromazobenzene, there can be little doubt that none of the bromine atoms in the tetra- bromo-derivative are in para-position to the nitrogen atoms.Experiments made with the object of preparing alkyl derivatives of hydrazobenzene have hitherto been uasuccessf ul ; when boiled with zinc chloridr: and alcohol, it yields benzidine. As the introduction of bromine into a coloured compound usually has the effect of heightening the colour, the conversion of azobenzene into a colourless bromo-derivative would seem to indicate that in some way the type changes : the tetra-derivative may well be a compound of the formula C,X,Br,*N~N*CGH,Br2. The formula generally attributed to azobenzene may, therefore, be regarded as unsatisfactory not oidy because it is a coloured substance, but also because it combines with bromine, &c., with a readiness which is unusual in the case of mono-derivatives of benzene ; because it yields a considerable proportion of a nzeta-monobromo-derivative and of a higher bromo-derivative in which, apparently, none of the bromine atoms are in pam-positions, an altogether unusual circum- stance in the case of benzene mono-derivatives other than those con- taining acid radicles ; and because it yields a coZourZess tetrabromo-derivative, The following formula would "account " for all these peculiarities, and in a measure "explain "the formation of benzidine and diphenyline as well as the recent remarkable observations on the production of diphenylamine derivatives from azobenzenoid compounds on reduction ; but it iseminently unconventional, and its adoption involves the re- cognition of a form of interaction not yet entertained by chemists :-N-- N II II A H H A DISCUSSION. Mr.GREEN considered that the relation of constitution to colour was a very important question both from a theoretical and practical point of view. The " quinonoid " hypothesis advocated by Dr. Arm-strong appeared to him to be the only satisfactory attempt which had been hitherto made to formulate a complete theory of chromogenesis. Witt and others had given us chromophores, chromogens, and AUXO-chromes, but these ideas were more names than theories, as no one had yet been able to predict what groups would be chromophores and 196 what not. The “quinonoid ” hypothesis, however, put us fairly on the road to predicting whether a compound of a certain constitutjion would be a dye-stuff or not, and might even eventually lead to the prediction of the shade and dyeing properties.He had given a good deal of attention to the subject recently, and although he had begun by regarding the “ quinonoid ” theory in a somewhat sceptical light, it had recommended itself to him more and more, as he found so many facts, hitherto inexplicable, which were explained perfectly simply by its means. He might instance the formation of rosaniline in the magenta-melt, which was readily explained by assuming the primary formation of an oxidation product of paratoluidine, viz., &C:C6H4:NH, which might then undergo alternate additions of aniline and reoxidations. He believed he had obtained this parent substance of the rosaniline series by oxidation of paratoluidine snlphate in acid solution, and it appeared to be identical with a substance described by Dr.Perkin as an isomer of parazotoluene. Again, the well known tendency of quinones to form substituted amidoquinones with amines explains the ready formation of such complicated products as safranine, the indulines, aniline-black, &c. He was inclined rather to attribute the cause of the colour in such “ quinonoid ” compounds to a strain set up within the benzene nucleus by two of the bonds ceasing to act centrally, than to the arrangement of these bonds outside the nucleus, Le., as intrn-nucleal rather than ides.-nucleal.On the “quinonoid” hypothesis, two groups of colours should be possible, viz., ‘* ortho-colours ” and para-colours.” The colours of the rosaniline series can only be formulated as para-colours, indigo only as an ortho-colour. On the other hand, many of the artiticial colouring matters may be viewed either as para- or ortho-colours ; thus niethylene-blue may be written :-ClMe2N:CsH3<N>C6H3*NMe2(paraquinonoid) , c1 N or Me,N*C6H,< S>C6H3*NMe21 (orthoquinonoid) . The speaker had recently examined a large number of colouriiig matters in regard to their hehnvionr towards reducing agents and the stability of their leuco-compounds, and had brought to light the remarkable fact that, whereas the leuco-compounds of the rosaniline aurin and phthalein colours were very stable, resisting air oxidation, the opposite was the case with the leuco-colours of the azine, oxazine, thiazine, acridine, safranine and induline series, which all oxidise in the air to the corresponding colours with extreme rhpidity.This was 197 also the case with leucindigo ar?d its sulphonic acid. The conclusion seemed to him to be irresistible, that the colours of the latter class were ortho-colours, whereas, the eosines, aurjnes, rhodaniines, &c., like the rosanilines, were pum-colours. Mr. FRISWELLagrecd tliat confirmahion of Dr. Armstrong’s riews was afforded by facts such as, for example, the colourlessness of t,ri-amidotriphenylcarbinol in comparison with the intense colour of its anhydro-base, which could be represented by a quinonoid formula.He, however, thought that the representation of colour as charac-teristic of a particular constitution was, for many reasons, to be deprecated, and that the remarkable effect of molecules external to the potential colour molecule in either developing or suppressing coJour required attention. In the case of trihydroxytriphenylca~~~inol, an apparently colourless substance, dour was developed by alkali, the salts being powerfully coloured ; and in the case of the interesting dye “pure scarlet ’’ discovered by E. C. Nicholson, which the speaker had himself studied, and which he thought was to be represented by the formula HO*C(C6H4*OH)2(C,H,MeNH,),both acid and alkali salts were coloured, although the substance itself was but feebly coloured.The sulphonic acids Gf triphenylrosaniline were powerful colours, but their combinations with alkalis almost colourless : so that wool dyed with the sodium salt of Nicholson-blue was nearly white until dipped into acid. This phenomenon was even more marked in Me1 dola’s alkali- green. Tn illustration of the fact that substances exactly similar in con- stitution behaved in remarkably dissimilar ways, the following experiment was then made :-Two tubes were taken : one contained roeaniline base, benzoic acid and aniline, the other triph enylrosanil- ine base, benzoic acid and aniline-the latter being of an intense blue, the former a feeble red, colour. On heating to a similar tem?erature, the rosaniline base combined with the benzoic acid, and the well known magenta colour was produced in the one tube ; while, in the other, the triphenylrosaniline base split off from the benzoic acid, and only the dull brownish feeble colour of the base wab noticeable.These facts showed :-1, the importance of factors external t,o the potential colour molecule; 2, the variations of behaviour of sub-stances containing similar potential colour molecules. Hence, he coii- sidered time not yet ripe for extensive generalisation as to the origin of colour in the benzene series. [Mr. Friswell’s argument is valid only if proof can be given that the coloured salts he refers to are carbinoZic ;there is no reason to suppose, at present, that the change which attends the formation of the rosaniline salts does not occur in all the cases he mentions in which coloured compounds result.-H.E. A.] Mr. JACKSOSenquired whether the vapour of quinone were coloured. Mr. LINGmentioned that diparaiodoaxobenzene had but a pale yellow colour. 76. “ The reduction products of dimethyldiacetylpentane.” ByF. Stanley Kipping, Ph.D., D.Sc. Itis shown that dimethyldiacetylpentane, CHMeAc.[CH,]3*CHMeAc, a diketone produced by the hydrolysis of ethylic dimethyldiacetyl- pimelate (Kipping and Mackenzie, 0.S. Trims.,1891, 569), is readily converted by reduction iito a mixture of approximately equal quan- tities of dimethyldihydroxynonane,and of a cornpound which, judging from the manner in which it is formed, may, it is thought, be regarded C H,*CHMe-$l Me.0He as tetramethyldihydroxyheptamethylene, cHz<CH2*CHNe*C Me.OH When the crude products obtained by heating a moist ethereal solu-tion of the ketone with sodium is submitted to steam distillation, a colourless oil, which has a peculiar and characteristic odour, slowly passes over, leaving as residue an almost odourless, practically non- rolatile oil. Excluding pinacones and other condensation products which miglit be formed, and which would be characterised by a very high boiling point, only three compounds can be produced by the reduction of the diketone, namely, the nbove mentioned and the ketonic alcohol CH3.COCHMe. [CH,] ,*CHMe*CH(OH) *CH3. As the non-volat ile oil has the composition Cl1HB4OZ, and yields a diacetyl derivative of the composition C,,H,OzAc,, it is to be regarded as dime thyldihydroxy- nonane.The volatile oil is not reduced on treatment of its solution in moist ether with sodium, and is not acted on by phenylhydrazine or hydr-oxylamine ; hence, it cannot be a ketonic alcohol of the constitution given above; it would appear probable, therefore, that it is a tetra-metbyldihydroxyheptamethylone. This conclusion is borne out by the great similarity in prqerties between the volatile oil and the di- methyldihydroxyheptamethyleiie previously described by Kipping and Perkin (C.S. Trans., 1891, 214), a resemblance which cannot fail to be observed when working with the two compounds. 77.“The products of the interaction of zinc chloride or sulph-uric acid and camphor. (Third notice.)” By Kenry E. Arm;trJng and 3’. S. Kipping. In a previous notice (these Proceedings, 1892, 54), in which it was shown that the crude product obtained on heating caiuphor with either sulphuric acid or zinc chloride contains 1: 2 : 4-acetyl-orthoxylene, reference was made to the presence of a constituent to which presumably the oil owes its strong, peppermint-like odour ; all attempts to separate this constituent by fractional distillation were unsuccessful, nor could it be recovered from the oil from which the acetorthoxylene-hydrazone had been separated by crystallisation. As it wxs observed that the crude oil readily decolorised an acid solution of permanganate, which has but little action on camphor and acetorthoxylene, a quantity of the oil from which t,hese latter had, as far as possible, been separated was submitted to oxidation ; ultimately an acid was obtained which has proved to be a-methyl- glutaric acid.As this acid is the characteristic oxidation product of the phorone obtained by distilling calcic camphorate, according to Konigs and Eppen, which has a strong peppermint-like odour, it is very probable that a homologue of this phorone is present in the camphor product, which has a higher boiling point than camphorone. 79. “ The Griess-Sandmeyer interactions and Gattermann’s modi- fication thereof.” By Henry E. Armstrong and W. P. Wynne. Having very frequently had occasion, during several years past, especially in the come of our studies of naphthalene derivatives, to avail ourselves of the marvellous improvements effected by Sand- meper in the Griess methods of displacing the miido-group by halogens, &c., we have been led to caret’ully study the conditions requisite for success, and have long since come to the conclusion that, in very many cases, much better results may be obtained by operat- ing at relatively low temperatures instead of at the boiling point as recommended in most cases by Sandmeynr.Experiments made at the request of one of the writers by Mr. Conroy with the object of comparing the yield in the case of the conversion of aniline into chloro-and cyano-benzene when operating :-I, in accordance with Sandmeyer’s original directions, 2, in accordance wit,h Gattermann’s directions, using finely-divided copper in place of cuprous salt, 3, in general accordance with Sandmeyer’s directions, but at lower temperatures, have led to the conclusion that, in the case of chlorobenzene, an in- finitely better yield is obtained by mixinq the cooled cuprous with the cooled diazo-solution, subsequently allowing the temperature to rise.It appears also that the Gattermann process affords a larger yield only in so far as it differs from the Sandmeyer process by being carried out at a lower temperature, and that it differs in no other essential particular from the Sandmeyer process ; there is, in fact, an entire absence of evidence that the copper acts as such, or except it has undergone conversion into cuprous salt. In the case of cyano- benzene, apparently the same advantage is not derived from carrying on the operation at a low temperature.The ‘‘ cold process ” has been found to be of advantage in many other cases. Several years ago, the preparation of large quantities of orthochlorotoluene was carried out in the Central Institution Laboratory essentially in the manner described by Erdmann in his recent paper in Liebig’s Annulen, and the yield was even better than that he obt,ained. Allusion is made to this in the paper by one of us on toluene derivatives (cf., these Proceedings, 1892, 139) which appears in the December number of the Transactions ; several other inshnces of the application of the cold process are mentioned there.We aze entirely in accord with EI-dmann as to the different and peculiar behttviour of the cuprous compounds of various diazo-derivat,ives; it is especially nobeworthy in the case of naphthalene derivatives that the temperature at wbich nitrogen is evolved varies for each compound, and that there is a temperature optimum at which the conversion should be effected to obtain the maxiinurn amount of pure product. There is no comparison, especially in the case of the iiaphthylaminesulphonic acids, between the two methods, colourless products being readily and almost immediately obhained by decomposing t,he diazo-cuprous compound at the favourable tempera- ture, whereas on heating to the boiling point coloured products, which obstinately resist purification, are obtained.There can be little doubt that the formation of “azobenzenes,” to which Erdmanii directs attention, is, at least, very largely the cause of this coloration. The difficulty met with in convertiiig betanaphthylamino into beta- chloronaphthalene, which Gattermnnn has specially noticed, is not got over by the cold process, a very large amount of a resinous con- densation product being always formed; a method of nbtaining a satisfactory yield of betachloronaplithalene directly from tile amido- compound has yet to be discovered. 8 0. “Methods of observing the spectra of easily volatile metals and their salts, and of separating their spectra from those of the alkaline earths.” By W.N. Hartley, F.R. S. The difficulty in obtaining pel-sistent flame spectra of lithium, potassium, rubidium, cesium and thallium has to some extent been surmounted by the contrivances designed by Mitscherlich, Gony, and others, bur, as solutions are necessary, these methods have not been found satisfactory by the author. It is shown how flame colorations lasting for long periods may be obtained by converting the salts into fiuosilicates, borates, or silicates. These compounds are less readily decomposed, and are more difficult to volatilise than the corresponding chlorides, sulphates, $c. Fused beads of the salts are held in the flame of a Bunsen burner on platinum wires, while measurements are made with the spectrometer.When observing in the usual manner, the spectra of the alkalis are liable to be obscured by the presence of lines and bntids due to the alkaline earths. By converting the material to be examined into R fluosilicate, borate or silicatte, the spectra of calcium, strontium and barium ai-e suppressed. If, however, the substance to be examined be converted into a borate, the alkali met.als can first be observed, and subsequently by passing hydrogen chloride gas into the flame, the spectra of the alkaline earth metals become brilliantly visible. Although visible, the green bands due to boric oxide are feeble, and cause no confusion. 81. '' Manganese borate, its constitution and properties." By W. N. Hartley, F.R..S., and Hugh Ramage.Particulars are given of the propeyties of manganese borate pre-pared in various ways from manganese sulphate and alkaline borates. Manganese borate dried in vacur, over snlphuric acid is found to lose to the extent of 11.84 per cent. of its weight water when heated at 100"; when heated from 100" to redness, it loses 19.65 per cent., which is water of constitution, the compound being a tetrahydric orthoborate, t'hus :-BOs.HzO, BOs Box, Mn(B02)~ Ignited to bright Dried in z'acIo. Dried at 100'. redness. By gradually heating the salt at fixed temperatures increasing to bright redness, and ascertaining the amount of water which it con-tained, a, series of numbers was obtained from which a curve was drawn, the ordinate numbers being the percentages of water in the compound, and the abscissEe the corresponding temperatures.It was thus seen that there were five points above 100"at which dis- sociation was interrupted and the compound in existence assumed :I condit.ion of stability. The following are the compounds of which the formation is inferred :- 202 Water contained in compound.Temp. of 7---Lp 7 formation. Found. Calculated. 22" 26.86 2'7.69 per cent. 100" 19-65 20.33 ,, 170" 11.45 11-32 ,, 195-220" 10.43 10-40 ,, 255" 9.71 9-61 ,, 295--305" 7.20 7.84 ,, Dull-red heat 2.87 3.09 ), Bright-red nil Partial fusion. The solubility of manganese borate in various saline solutions was investigated : it was found to possess a nia,ximum of solnbility at or about 18",and a minimum at 80", so that when solutions are heated, they deposit the salt at this temperature.It is believed that this is caused by the dehydration of the salt in solution, namely, MnH~(R03)2,H,0, which becomes Mn F,(BO,),, and this, being less solnble, is deposit,ed : such a change being known to occur, and to be complete at 100" when the salt is heated in air. Extra Meeting, December 13th. An extra meeting of the Society will be held on Tuesday, Decem- ber 13th, at 8 P.M., the anniversary of the death of Stas. A paper, specially prepared for the occasion by Professor J. W. Mallet, F.R.S., entitled "Jean Servais Xtas, and the measurement of the re- lative masses of the afonis of the chemical elements," will be read and discussed. At the meeting on December 15th, there will be a ballot for the election of Fellows. The following papers will be read :-" The identity of caffeine and theine." By Prof. Dunstan and Mr. Shepheard.'' Studies on isomeric change." By Dr. Moody. HARRISON AND SON& PBINTEBS IX OUDINABY TO HER MAJESTY,ST.MABTIN'S LANE.

ISSN:0369-8718    

DOI:10.1039/PL8920800185

出版商:RSC    

年代:1892

数据来源: RSC