BUCHTON ON THE STIBETHYLS AXD STIBXETHYLS. 115 XII.-On the Stibethyls and Stibmethyls. BY G. B. BUCKTON, Esa. F.R.S. CHEMISTSare already aware through the researches of Dr. Hofmann that zinc-ethyl reacts on terchloride of antimony in a manner similar to that shown by terchloride of phosphorus;-in the former case triethplstibine is formed in the latter case tri- ethplphosphine. The same successful labourer in this field of chemical inquiry in his profouiid and complete history of am-monia lately communicated to the Chemical Society groups these bodies as primary triamines or amrnonias in wliicli antimony and phosphorus severally play the parts of nitrogen and three equiva- lents of ethyl those af hydrogen. The following experiments were undertaken with the intention of testing how far the compounds of antimony with methyl and ethyl were limited to the ammonia-type and more particularly to determine whether by assimilating more than three in olecules of methyl &c.bodies might arise referable to the types of anti-monious and antimouic acids. 12 I16 BUCHTON ON THE Triethylstibine is known to combine with two equivalents of chlorine or iodine to form its haloYd salts. If substitution could be effected through zinc-ethyl in these substances a pentethylated radical mould arise showing the antimony in a complete condition of saturation. Coarsely powdered antimony attacks iodide of ethyl readily when sealed in tubes and exposed to a temperature of about 140" C. An oily liquid is formed composed of biniodide of triethylstibine with probably a little teriodide of antimony.This biniodide Sb(C,H,),I, produces considerable heat when mixed with zinc-ethyl a pasty mass being formed upon the surface of which a yellowish liquid floats. Distillation is attended by an abundant evolution of inflammable gas which is charged with the vapour of triethylstibine. To remove as far as possible the inconvenience of these dense white antimonial fumes the first distillation is best performed in a quilled receiver the tube of which is plunged into water. The yellowish heavy liquid obtained as above mas rectified in an atmosphere of coal gas. The first portion contained a little ether which ras separated after which the temperature rose to 150° between which and 170' C.all the liquid products passed over. The fraction boiling below 160' C. had the properties of triethylstibine but gave numbers slightly higher than those re- quired by theory Theory. Experiment. h -Sb '129 59.73' -Cl 72 33.33 33.51 33.97 Hl 15 6-94! 7.17 7.39 216 100.00 Triethylstibine when pure is a colourless and limpid fluid having a faint odour which can scarcely be styled alliaceous. An unpleasant and very persistent taste is left in the mouth when a small portion only of its vapour has been inhaled. It is spon-taneously inflammable in air but may be kept unchanged under a layer of water. It mixes with bromine under water without disengaging any noticeable quantity of gas and the oily bibromide of triethylstibine is formed.With hydrochloric acid hydrogen gas is liherated acd the corresponding non-fuming bichloride is produced. Triethylstibine is a very stable body and distils withont STIBETHYLS AND STIBNETHYLS. 117 change. Here it differs from Stanethyl which as Dr. Frank-land has shown deposits when heated half its quantity of tin and passes into stannic diethgl. Lowig and Sch weitz er found the boiling point of triethylstibine to be 159' C. 'A combustion of the samples boiling between 160' and 170' C. showed a considerable increase in the percentage of both carbon and hydrogen. Although the numbers obtained approach more nearly the com- position of tetrethylstibine than that of pentethylstibine it is thought more probable that the latter rubstance is really con-tained in the mixture.The percentage of carbon and hydrogen. was not increased by another rectification of the sample and it soon became evident that the body was broken up by heat. This observation furnishes an explanation of the copious liberation of gas noticed during the distillation of biniodide of triethylstibine with zinc-ethyl. Tetrethylstibine. Sample 1. Sample 2. Sb 129 52.65 -1- _. C, 96 39.19 37.51 37.44 35.96 35*4<4 €I2(-) 20 8-16 7.90 8.01 7.43 7.39 245 lOO.80 The decomposition of such a body by heat is analogous to that of pentachloride of antimony ~hich is thus known to yield chlorine gas and the terchloride In the same manner The existence of a stibium compound containing more than three molecules of ethyl was confirmed by the deportment of the sample under examination towards bromine.A portion of the fuming liquid was thrown up into the head of an eudiometer tube standing over mercury and small quantities of bromine were introduced from time to time. The mixture was attended with a violent action and a bulk of permanent gas was formed. As the neutral point was approached all visible action ceased but when the bromine was in slight excess a partial absorption of gas was noticed. As triethylstibine unites with bromine to form the bibromide without liberation of gas the appearance of ethylene and hydride of ethyl can only be explained by the presence of a more complex ethylated radical than triethylstibine 118 BUCKTON ON THE The absorption of gas also would thus be easily explained.Sb(C,H,) + 4Br = Sb(C4HJ3Br2 + C,H,Br + C,H,H. Triethylstibine passes into the non-fuming bichloride also more readily with concentrated hydrochloric acid than the substance here described which loses its character of spontaneous inflam- mability only after long boiling. It is remarkable that zinc-ethyl is not attacked by bichloride of triethylstibine even when the mixture is raised to its boiling point. The most characteristic salt of triethylstibine is the bisulphide which is easily formed by heating the radical with alcohol and sulphur. It crystallises in long silky needles which are readily soluble in water. This salt is rapidly decomposed by boiling in excess of aqueous cyanide of potassium.The cyanide is in this manner converted into sulphocyanide of potassium aud triethyl- stibine is liberated in white fumes. If the mixture containing the higher stibium-radical be boiled with alcohol and sulphur there is formed together with bisulpliide of triethylstibirie a corisiderahle quantity of bisulphide of ethyl. This substance becomes immediately evident by its powerful and repulsive odour. Although triethylstibine is remarkably persistent in itself its salts are in general easily reduced. The most convenient method of obtaining the radical triethpl- stibine is by distilling its salts with granulated ziiic. As the biniodide is easily formedj it is well suited for such an operation. The action is set up with some euergy ad the products are most corivcriiertly received under water.7 have failed in forming substitution-products by bringing to- gether trietliplstibirie and bisulpliide of carbon. The satrie failure also has happened in my attempts to cause a reaction between triethjlbtibine and t,ibromide of ethylene. AK~ interesting body from trictii ylpliosphine hornologous to sulphocar barnate of ammonium has been obtairied by Hofmann (C2S2)’’E,P 2PE3 + C2S4 = Witti triethylstibine the tubes invariably burst at a temperature of 240”C. and below this point no change appeared iu the materials. STIBETHYLS AND STIRMETHYLS Having some quantity of triethylstibine at my disposal a few experiments in confirmatiou of those of N.Lijwig were made.On the Salts of Tetrethylstibine. Triethylstibine was mixed with a slight excess of iodide of ethyl. In the course of it few hours a mass of fine crystals of iodide of tetrethylstibine was obtained. Iodide of tetrethylstibine when mixed with zinc-ethyl and distilled yields the same results as if biniodide of triethylstibine had been employed. Iodide of zinc fixed gases and a mixture of two radicals incapable of separation by heat were obtained. Oxide of Tetrethytstibine is very soluble in water and is un- crystallizable. When heated ahove 100' C. it undergoes decom- position with liberation of white fumes of triethylstibine. Sulphate and nitrate of tetrethylstibine are crystallirie salts. Chloride of Tetrethy lstibine is also crystalline.When dissolved in water and mixed with bichloride of platinum it yielded a fine yellow crystalline salt which was but little soluble in alcohol. When ignited and separated from the antimony the following analytical result was obtained. 0.7856 grm. of salt gave 0-1752 grm. of platinum which accords most nearly to the formula Sb(C!,H,),Cl.PtCl Theory requires. Found. Sb . 129.0 28.63 7 C16 H,,c1 ' . . . . 96.0 20.0 106.5 21-30 4.44 23.65 -- Pt . . 99.0 21-98 22.31 450.5 100.00 Lawig obtained a salt much richer in platinum to which he assigns the composition 3I?tCl, 2(Sb(C H5)*C1). Action of Zinc-methyl on Biniodide of Trimethystibine. As the methyl-molecule is simpler in structure than that of ethyl it was thought that a penta-methylated body might possibly resist decomposition during distillation.The biniodide of tri-methylstibine may be obtained in beautiful crystals by acting on BUCICTOX ON TIIE metallic antimony with iodide of methyl at a temperature of 140"C. As these crystals were found to decompose zinc-methyl energetically an appeal TF as again made to experiment. The materials were mixed slowly in a retort and after the first action had subsided the mass mas submitted to a temperature of 100' in a water-bath which removed the excess of zinc-methyl and ether. Subsequently the distillation of the solid mass was com- pleted over the sand bath. In this way a heavy pale-coloured liquid was obtained which after agitation with water and weak acid was rectified in an atmosphere of coal gas heat being applied by a water-bath.Fractions were tzken between 8Oo-86O 86'-96' 96°-1000 C. All these samples had the following properties They were oily bodies with faint oclours hca-vier than water with which they did not mix. When exposed to the air they were not spontaneously inflammable neither did they at ordinary temperatures give off white fumes. When dropped on a warm surface however they ignited and burnt with a luminous flame accompanied by a dense mtimonid cloud. The following numbers were obtained by analysis of these samples :-86"-96' -.-80"-86" 96"-IOO0 -31.64 -, 21-99 Carbon . . 21.20 26-90 30.18 Hydrogen . 5.08 5.23 5.92 6.83 6.98 Fw comparison the numbers required by theory for antimony with three four and five equivalents of methyl are appended.-7- Sb Me Sb Me4 Sb Me Sb 74-25 Sb 68.37 Sb 63-19 C 20.69 C 25.39 C, 29.46 H9 5*1G €Il2 6.34 H, 7.35 100.00 100.00 100.00 Notwithstanding the circumstance that the above samples are not spontaneously inflammable (a cham cter pre-eminently shewn by trimethylstibine) the composition of No. 1 seems to indicate its identity with that body. Before being confident with reference to the composition Qf Nos. 2 and 3 some weight must be given to an observation here made viz. that in the decomposition of zinc- methyl by a high temperature instcad of gases being eliminated as is known to be the case with zinc-ethyl hydro-carbons are pro- STIBETHYLS AMD STIBNETRYLS.duced which burn with a smoky flame. These substances I have not yet been able to examine but it would appear that the methyl- molecules undergo dupiication and thus give rise to bodies pos-sessing high boiling points. It is therefore possible that pentamethylstibine may be resolved by heat into trimethylstibine and such a hydrocarbon. This would account also for tlie excess in the carbon and hydrogen given by analysis of sample No. 3. In conclusion it is thought that a reviewal of these experiments in both the ethyl and methyl series will justify the conclusion that the higher stibium organo-radicals exist. A better method for their isolation however is still a desideratum. Apparatus for general fractional Distillation in Carbonic Acid Gas.A. Inverted bell glass with open neck. B. Stand with thick vulcanized indian rubber collar E. C. Circular table with sockets for holding bottles 1 2 3 &c. D. Thick glass rod sliding air-tight through col- lar and stand by which the table and bottles may be raised lowered or rotated at pleasure. P. Quilled re-ceiver and retort. I.and K. Tubes for entrance and exit of c'arbonic acid or other gas. C. Clamp with forked arm to secure the bell to the stand and permit the table to rotate eccentrically if required. The tube of the receiver may thus be introduced into any one of the bottles. H. Slate cover which may be ground to fit the lip of the bell or simply luted to it with linseed.