FltAXKLhNUj ON ORGANO-METALLIC BODIES. 172 XIX.-On Organo-metallic Bodies. A Biscourse delivered to the MemFiers of the Chemical Society of London BY DR. E. FRA4NKLAND F.R.S. ALTHOUGH organo-metallic bodies as a distinct class of organic compounds are with one exception the creation of the last ten years yet the derivatives of these bodies have been known for a much longer period. From the time that an organic acid was first united with a metallic base these organic compounds containing metals date their existence. It is true that such compounds con- taining a metallic constituent have not bcen regarded from this point of view; but a little consideration will serve to show that they stand in the same relation to organo-metallic bodies in the strict sense of the term as the ethers alcohols acids and numerous other organic families occupy with regard to the alcohol-radicals from which they are derived.Thus zinc-ethyl yields by oxidation ethylate of zinc ZnC,H + 0 = ZnO,C,H,O Zinc-ethyl. Ethylate of zinc. a body which although unknown until formed by this reaction has undoubted and well-known analogies in the ethylates of potash and soda. By suitable processes of oxidation ethylate of zinc may be con- verted into acetate of zinc. ZnO,C,H,O + 0 = C,H,ZnO -i-E,O Ethylate of zinc. Acetate of zinc. The ethyl-compounds of potassium and sodium also pass through analogous phases of Oxidation. Again potassium-ethyl and sodium-ethyl under the influence of carbonic acid yield the propionates of potash and soda II;C,H + C,O = CGH,ICO Potassium-e thy I.Propionate of potash. NaC,H + C,O = C,f-E,NaO -* Sodium-ethyl. Propionate of soda. VOL. XIXI. N 178 FRANKLAND ON ORGANO-METALLIC BODIES. The same result may also probably be reached by two distinct stages viz. first by the conversion of potassium-ethyl and sodium-ethyl into the ethylates of potash and soda KC,H + C4H,0 KO Potassium-ethyl. Ethylate of potash. and secondly by the action of carbonic oxide upon these bodies C,H,KO + C,O = C,H,KO Ethylate of potash. Propionate of potash. The second stage of this conversion has not yet been experi- mentally realized but Berthelot's ingenious production of formiate of potash from carbonic oxide and hydrate of potash exhibits an homologous reaction.These examples serve to point out the relations existing between organo-metallic bodies in the usual acceptation of the term and that far more numerous elass of derivatives to which the same name might without impropriety be applied; and it is now only necessary to remark that the present discourse will be confined to the consideration of organo-metallic bodies in the usual and more restrieted sense of the term. Formation of Organo-metallic Bodies Organo-metallic bodies admit of being produced by a great variety of processes; but these numerous methods of formation with very few exceptions admit of being grouped under four heads. 1. Formation by union of the oyganic radical in statu nascenti with the metal.TJpon this method depends the production of zinc-ethyl the reaction being usually expressed by the following equation Iodide of ethyl. Zinc-ethyl. It is however very doubtfnl mhether this equation correctly expresses the actual change which occurs in the production of zinc-ethyl. It has long been known that this body is found in a free state in very small quantity only amongst the products of the FRANKLAND ON ORGANO-METALLIC BODIES. reaction of zinc upon iodide of ethyl but that there exists amongst these products a crystalline body which contains zinc ethyl and iodine and which may be regarded as formed according to the equation Iodide of ethyl. Ethiodide of zinc. This compound is decomposed at about 150' C yielding iodide of zinc and zincethyl Ethiodide of zinc.Zincethyl. Contemporaneously with the first of the above reactions there occw others in which ethyl hydride of ethyl and ethylene are produced. The separation of ethyl in this reaction is doubtless due to the direct action of zinc upon iodide of ethyl Iodide of ethyl. Ethyl. whilst the appearance of the secondary products ethylene and hydride of ethyl results from the action of the ethiodide of zinc upon iodide of ethyl Ethiodide of zinc. Iodide of ethyl. Hydride of ehtyl. Ethylene. a view which is supported by the behaviow. of sodium-ethyl in contact with iodide of ethyl.* 2C4H5' = 2C,€f4 + 2'4%) + ZKI I< {cjr+ Ii CH Potassium-ethyI. Iodide of ethyl. Ethylene. Hydride of ethyl. Notwithstanding the intermediate stage just indicated in the production of zinc-ethyl the final result of the reaction is correctly expressed in the first of the above equations.* Proceedings of Royal SOC. vol. ix p. 345. NfZ 180 PRANKLAND ON ORGANO-METALLIC BODIES. Zinc-methyl and zinc-amyl are produced in a perfectly analogous manner but no attempt has yet been made to form the corre- sponding compounds of the remaining alcohol -radicals. The hame method of formation yields cadmium-ethyl," when iodide of ethyl is digest& with cadmium at a teingcrature of from looo to 150" C. Iodide of ethyl. Cadmium-ethyl. In this case also there appears to be an intermediate stage in the process probably quite analogous to that noticed in the production of zinc-ethyl.The temperatwe at which the ethiodide of cadmium thus formed is decomposed (177O C.) is considerably higher than that required for the decomposition of the corresponding zinc -cornpound in consequence of which a small proportion only of cadmium-ethyl is obtained the remainder being broken up into other products This circninstance has hitherto prevented the complete inves-tigation of cadmium-ethyl. The experiments of Wanltl yn how-ever scarcely permit its existence to be doubted. No other organo-cadmium cornpoimds have been formed. Treated with iodide of ethyl magnesium gives magnesium ethyZ,t the reaction commencing briskly at ordinary temperatures but requiring a heat of 120° C to 13Q0C for its completion ______~ Iodide of ethyl.Magnesium-eth yl. The honiologous reacticn with iodide of iricthyl appears also to yield magnesiztm-methy1.S Similarly treated aluminum yields at temperatures from 100' to 130' C aluminium-ethyl and aZzcnzinium-metly~.§ 3',7) i-Al = (A12 *Wnnlrlyn Chcm. SOC. +Cahours Aim. Ch. Phjs. [3] hii 17. FHANKLABD ON ORGANO-METALLIC BODIES 181 Double compounds of aluminium-ethyl and aluminium-methy 1 with the iodide of aluminium are here formed and the orgaiio-aluminium bodies have not yet been obtained with certainty free from iodide of aluminium. GZucinunz-ethyl* appears also to be formed under similar cir- cumstances hut its existence has not yet been confirmed by analysis. Orgnno-compounds of Tin.-Although these bodies can be obtained by other processes the general method we are noxv considering is doubtless the most convenient mode of producing most of them.Tin is capable of forming three distinct classes of binary inorganic compounds which may be represented by the following general forinulz Sn R sn2{:R i:t R This threefold atomic character of the metal tin renders the result of its action upon the iodides of the alcohol-radicals con- siderably less simple than those we have hitherto considered. Without taking into account compounds to which a still more complex constitution has been assigned the existence of the following series of orgxno-metallic bodies containing tin has been cstablisfied :j- 1st Series. 2nd Series. 3rd Series. R+ R+ R+Sn {R+ R- 4th Series.5th Series. 6th Series. The second and fourth of these series have not yet been produced by the method we are now considering. * Cahours Ann. Ch. Phgs. [3] lviii 22. 4-In these formula?R + represents a poaitive organic radical and R-a negative radical no negative organic radical as such has yet been introduced into these compounds. fa FRANKLAND ON ORGANO-METALLIC BODIES. FIRSTSERIES. Stannous ethide ( Sn2 {$;:) is produced in small quantities by the action of heat upon a mixture of iodide of ethyl and tin Iodide of ethyl. Stannous ethide Stannous methide is daub tless formed under similar conditions Iodide of methyl. Stannous methide. The TmRD SERIES of stann-organic compounds~ are formed by the following reactions + SnI Iodide of methyl.Dimethiodide of tin + SnI Iodide of ethyl. Diethiodide of tin. FIFTHSERIES. The following chemical changes express the mode of formation of compounds belonging to this series Iodide of methyl Stannic Iodotrirnethide. Lodide of ethyl. Stannic Iodotriethide. SIXTHSEnms.-The most abundant products of the action of tin upon the iodides of the alcohol-radicals belong to this series; indeed if the action be produced by light instead of heat this series of bodies is formed almost to the complete exclusion of the FRANHLAND ON ORGANO-METALLIC BODlEh $83 others. It is necessary however to remark that the materials exposed to light should be completely excluded from atmospheric oxygen otherwise the liquid assumes an orange colour and the action is so effectually arrested that an exposure for several months to sunlight concexltrated by a parabolic mirror will scarcely pro- duce any appreciable change.The following reactions explain the formation of bodies belonging to this series Iodide of methyl. Stannic dimethiodide. Iodide of ethyl Stannic diethiodide. Iodide of amyl. Stannic diamyliodide. It is evident that three series of tin-compounds are still wanting to complete the category viz. It is somewhat remarkable that no organo-tin compounds con-taining only one equivalent of positive radical have hitherto been produced. The inference to be drawn from this that such bodies do not exist must be checked by the fact that no special attempts have yet been made to form them.Organo.compounds of Mercury.-The reaction of mercury upon the iodides of the alcohol-radicals gives rise to two series of organic compounds the general formula of which may be thus written 184 'I;"RA.NHLAND ON ORGANO-METALLIC BODIES. 1st Series. 2nd Series. The first series only of these bodies can be produced by the general mode of formation now under consideration; but the members of the second series are readily obtained by the action of an organo-zinc compound upon those of the first. For the production of the first series of these bodies the action of light is essential except in the case of mercuric iodo-allide no elevation of temperature being capable of producing the chemical change.The following equations sufficiently exhibit the nature of the reaction Iodide of methyl. Mercuric iodomethide. Iodide of allyl. Mercuric iodo-allide For the production of the methyl-compound bright sunlight may be employed; but the reaction for the ethyl-body must be conducted in diffused daylight only otherwise no organo-metallic compound will be produced the ethyl being eliminated chiefly as such but partly also as hydride of ethyl and ethylene Iodide of ethyl. Ethyl. ~.~ Iodide of ethyl. Hydride of ethyl. Ethylene. In addition to these bodies compounds containing arsenic and antimony can also be produced by this general mode of formation; but they are obtained with greater facilitj by the second method which will now be described.FRANKLAND ON ORGANO-METALLIC BODIES. 185 2. Formation of organo-metallic bodies by the action of the respec-tive metals alloyed with potassium or sodium upon the iodides of the alcohol-radicals. The principles involved in this second general mode of produc-tion are essentially similar to those in the first but there is here less tendency to form compounds containing negative as well as positive radicals. This method although not capable of such general application is more especially adapted to the formation of the organic compounds of the polyatomic metals. The simulta- neous production of an organo-potassium or sodium compound need not be feared since such compounds cannot exist in the presence of the iodides of the alcohol-radicals.This mode of formation mill be sufficiently illustrated by the following reactions Jodide of methyI. Cscodyl. Iodide of ethyl. Ethxl-cacodyl. Iodide of methyl. Trimethylarsine. Iodide of ethyl. Trieth ylarsine. As Na {: = 3NaI Iodide of methyl Iodide of tetra-methylarsonium 4'4:5! ia 6 FRAISKLAND ON ORGAXO-METALLIC BODIES. + As{: Na + 3NaI Iodide of methyl Iodide of tetra-eth ylarsonium. Antimony-compounds. Iodide of methyl. Trimethylstibine. Iodide of ethyl. Triethylstibine. 3'10:11[ + Sb Iodide of amyl. Triamylstibine. Jodide of methyl. Iodide of tetra-methylstibonium. Iodide of ethyl. Iodide of tetre-thylstibonium. Iodide of amyl. Iodide of tetra-mylstibonium. FRAQNHLAND ON ORGANO-METALLTC BODIES.187 Tin-compounds. Iodide of methyl. Stannous-methide. Iodide of methyl. Stann-sesquimethide. Iodide of methyl. Stsnnic methide. Analogous reactions also represent the formation of the corre- sponding compouncis containing ethyl and amyl. Lead-compound. C,H5 3'4;5) + Pb Na = Pb C,H5 + 3NaT {:I {C,H5 Iodide of ethyl Plumb-sesquiethide Bismuth-compound. 3c4p) + Bi Iodide of ethyl Bis-triethide Tellurium-com~ounds. Organo-tellurium compounds are formed by a modification of this method which consists in distilling telluride of potassium with sulphovinate of potash and its homologues. 2(C,H30.S0 + KO.SO,) + 2KTe = Te {C2H3 + 4(KO.SO3) C,H Sulphomethylate sf potash. Tellurium-methyl. The ethyl and amyl compounds are prepared by homologous reactions.3. Formation of organo-metallic bodies 6y the action of the zinc- compounds of the organic radicals upon the haloid compounds either of the metals themselves or of their organo-derivatives. For the production of organo-metallic bodies containing less positive metals than zinc this method is perhaps not only the most 188 FKANKLAND ON ORGANO-METALLIC BODIES. convenient but also capable of the most general application. Com- pounds containing mercury tin lead antimony and arsenic have been thus produced but it has failed when applied to the haloid compounds of copper silver and platinum for although these bodies are violently acted upon the organic group does not unite with the metals.The following reactions represent the present state of our lrnow-ledge with regard to this method of formation :-Mercury-corn,ounds. ____ -___ Zinc-methyl. i’vlercuric methide. Zinc-me thyl. Mercuric chloromethide. Zinc-ethyl. Mercuric chlorethide. Mercurous ethide and mercurous methide have not yet been obtained either by this or any other process. The instability of mercurous compounds as sem in the inorganic oxide and iodide is brought to a climax in organic mercurous compounds; the latter are instantly transformed into metallic mercury and the more stable organo-mercuric compounds. Thus when zinc-ethyl acts upon mercurous chloride the following change results :-+ Hg + 2ZnC1 Zinc-ethyl. Mercuric ethide. Tin-compounds. FRANKLAND ON ORGANO-METALLIC BODIES.189 Zinc-ethyl. Stannic diethiodide. Xtannic ethide. Zinc ethyL Chlorotriethicic of tin. Zn + Zinc-ethyl. Stannic dichlorethide. Zinc-ethyl. Ziucostsnnous ethide. Zinc-ethyl. Strtnnic di-iodoe thide. Stannic diethylomethide. ____-_I Zinc-ethyl. Stannic iodo-trimethide. Stannic ethylotrirnethide. Lead-compomd. The following is the only reaction mhich has hitherto been effected by the method mhich we are now considering :-Zinc-ethyl. PliimLic ethide. Antimony-compoulzds. Zinc-me thyl. Trimethylstibine. 190 FRANKLAND ON ORGA4N0-METALLIC BODIES = (C*E-I52Sb C,H5 + 6ZnC1 b4H5 Zinc-ethyl. Triethylstibine. Arsenic-compounds. + 2As{: C1 = 2As{C2H3C2H3 + 6ZnC1 C,H Zinc-methyl.Trimethylarsine. Zinc-ethyl. Triethylarsine. 4. Formation of organo-metallic bodies by the displacement of a metal in an organo-metallic compourcd 6y another and more positive metal. Wanklyn to whoin we are indebted for this mode of formation regards this displacement of one metal by another as 8 case of true electrolytic decomposition. He thinks that in zinc-ethyl for instance ethyl is the electro- negative arid zinc the electro-positive member sodium being more electro-positive than zinc replaces the latter metal and forms sodium-ethyl. But he supposes that where the original organo-metallic body contains a metal less electro-positive than the hydrocarbon radical then the latter and not the metal would be eliminated by contact with a more positive metal.Cacodyl for instance when treated with sodium should give methyl and arsenide of sodium AS {:& + ~a,= AS + E;;;') Cacodj1. Arsenide of sodium. Methyl. This view the correctness of which is more than probable is supported by the action of potassium and of zinc-ethyl upon ammonia Ammonia. Potsssamide. FRANKLAND ON ORGANO-METALLIC BODIES. 191 Ammonia. Zincethyl. Zincamide. Hydride of ethyl. In accordance with this hypothesis Wan klyn considers that the ethyl in sodium-ethyl would be displaced by copper mercury platinum &c. and that sodium-ethyl is only in equilibrium with bodies whose respective positions in the electrical scale are either both of them within or both of them without the space lying between the electro-positive sodium and the electro- negative ethyl This fourth mode of producing organo -metallic bodies has hitherto been applied only to the formation of sodium and potassium compounds or rather double compounds of these bodies with zincethyl according to the following reactions Zincethyl.Double compound of sodium-ethyl asd zinc-ethyl. Zincet hy I. Double compound of potassium-ethyl and zinc-ethyl. Sodium also displaces mercury from mercuric ethide sodium-ethyl seems to be formed but the exact nature of the reaction has not been ascertained PROPERTIESORGANO-METALLIC OF BODIES. The organo-metallic compounds as a class are distinguished for the extraordinary energy of their affinities. With certain excep- tions presently to be noticed their disposition to unite with negative elements increases with the positive character of the metal and with the smallness of the atomic weight of the alcohol- radical.Thus organo-potassium and sodium compounds possess more chemical energy than those of zinc whilst the latter are more active than the compounds of arsenic antimony tin or lead. Again in the series belonging to each metal the methylic com- pounds are more energetic than the ethylic ones whilst the last greatly surpass the amylic compounds in this respect. But whilst 192 PRANKLAND ON ORGANO-METALLIC BODIES. these general principles govern the chemical energy of organo-metallic bodies their effect appears to be modified by the degree of saturation in which the metal exists.Although this circum- stance has hitherto received only very partial elucidation yet we have evidence of its existence in the case of organo-tin compounds. Both stannous ethide and stannous methide com- bine directly with atmospheric oxygen and the union takes place with tolerable rapidity ; but neither stannic ethide nor stannic methide is in the least degree acted upon by free oxygen at ordinary temperatures; even iodine acts upon them with difficulty. This diminution of chemical energy in organo-stannic compounds cannot be ascribed to the mere influence of the additional weight of hydrocarbon which they contain since stannous aniylide readily unites with free oxygen at ordinary temperatures although the single molecule of amyl which it contains is considerably heavier than the double atom of either methyl or ethyl present in the organo-s tannic compounds just cited.Organo-metallic compounds in a state of partial saturation play the part of compound radicals. They are uniatomic biatomic teratomic or quadratomic according to the number of molecules requisite to complete their saturation. On the other hand organo-metallic bodies in a state of saturation never perform radical functions they never undergo cliemical change without decomposition. Thus zinc-ethyl stannic ethide mercuric ethide and plumbic ethib all give substitution-products when they are chemically acted upon. The description of the special properties of the organo-metallic bodies may be conveniently commenced with the most positive of the class viz.Potassium and sodium series.*-These bodies have not yet been isolated; they are known only in combination with the corre-sponding zinc-compounds. The double compound of sodium-e thy1 and zinc-ethyl is the only one which has hitherto been submitted to analysis. Its formula is This compound first separates from its solution in zinc-ethyl as a transparent fluid which after some time solidifies to :t mass of large tabular crystals fusing at 27" C. but when once fused * Wanklyn Proceedings of Poy. SOC.,iu 341. FRANKLAND ON OBGANO-Bf ETALLIC BODIES 193 remaining fluid at several degrees below that point. On the application of a moderate heat gases are evolved and a mixture of sodium and zinc without carbon is left behind.The double compound decomposes water with great violence forming hydride of ethyl and the hydrated oxides of zinc and sodium. The behaviorxr with negative elements has not yet been studied. Its most interesting reaction consists in the absorption of carbonic acid which it transforms into propiouic acid. The sodium-ethyl alone takes part in this reaction :* Sodium-ethyl. Propionate of soda. A similar double compound containing sodium-lmethy.8 as well as the potassium-compounds of ethyl and methyl have been formed. They have not yet been completely investigated but it is believed that their coniposition and properties are perfectly analogous to those of sodium-ethyl No compoiind of any of these bodies with a negative element has been obtained.Their action upon carbonic acid proves that they possess a still higher reducing power than the corresponding organo-ziric compounds and they will therefore doubtless prove valuable agents for the substitution of positive groups for negative elements in cases where organo-zinc cornpounds fail to produce the desired effect. Sodium-ethyl decomposes the iodides of the alcohol-radicals in the cold with formation of iodide of sodium.? _ _ -~ Sodium-ethyl. Iodide of ethyl. Hydride of Ethylene. ethyl. Owing to this behaviour potassium and sodium compounds can only be prepared by method No. 4 Mugnesium series. $-The compounds containing ethyl and methyl only have hitherto been examined and the former alone submitted to analysis.These bodies possess a close similarity to * Wanklyn Chem. Soc Qu. J xi 103. I-Frank 1and Proceedings of Boy. SOC.,ix 345. $ Cnhours Ann. Ch. Phys. Iviii 17. VOL. XLII. 0 1$& FRANKLAND ON ORGANO-METALLIC BODIES. organo-einc compounds. Tkey are very volatile colourless liquids possessing a powerful alliaceous odour ; are spontaneously inflam- mable and decompose water with violence. They do not readily decompose the iodides of the alcohol-radicals and can therefore be prepared by method No. I. No compound of these bodies with negative elements has yet been produced They are in the condition of chemical saturation. Further details of their proper- ties are wanting. Aluminium and Glucinum series.*-Like the organo-compounds of the alkaline metals the aluminirim and glucinum compounds have not yet been isolated with certainty; they are known only in combination with the iodides of the respective metals and the composition of the ethyl and aluminium body only has been fixed by analysis.Its formula is These double compounds possess great chemical energy ; they are spontaneously inflammable volatile liquids which decompose water with explosive violence. They are attacked by zinc-ethyl forming iodide of zinc and very inflammable liquids which latter are believed to be the pure organo-compounds. They appear to be chemically saturated bodies and therefore incapable of direct combination. Further details are wanting. Zinc series.t-Three bodies belonging to this series are knomn vis.Zinc-amgl They are colourless transparent mobile volatile and odorous liquids composed of four gaseous volumes .of the hydro-carbon * Cahours Ann. Ch.Phys,,Iviii,20. 1.Frankland Chem. SOC.Qu. J. ii 297 and iii 44; Phil. Trans. cxlii 431 and cxlv 259. Wanklyn Chem. SOC.Qu. J. xiii 124. FRANKLAND ON ORGANO-METALLIC BODIES. 195 radical and two volumes of zinc-vapour the six volumes condensed to four. The methyl and ethyl compounds are spontaneously inflammable burning with a greenish blue flame. All three are saturated compounds incapable of direct combination. In contact with water they are instantly decomposed with formation of oxide of zinc and hydride of the organic radical. Zinc-methyl. Hydride of methyl.-. Zinc-ethyl. Hydride of ethyl. Gradually treated with oxygen so as to avoid too violent action they form the respective zinc-alcohols. Zinc-methyl Nethylate of zinc. Zinc-ethyl. Ethylate of zinc. Zinc-amyl. Amylate of zinc. The action of iodine upon organo-zinc-compounds consists in the transformation of both their constituents into iodides. +-I = 2~n1 + 2'2Pl Zinc-methyl Iodide of methyl. 02 196 FRANKLAND ON ORGANO-METALLIC BODIES. Zinc-ethyl. Iodide of ethyl. I = 2ZnI +2 Zinc-amyI. Iodide of amyl. Organo-zinc compounds behave in a manner exactly analogous in contact with the other halogens. Reactions like the foregoing point to the applicability of these cornpounds for effecting the substitution of positive groups for negative elements in compound bodies an application which has not failed to attract the notice of chemists.In addition to the reactions of this class given above as esamplcs of the formation of organo-metallic bodies by the third method the following have been realized With Binoxide of Nitrogen.* CH =2 NCHO ~(N,o,) +Zn jCgHs 2 2 5,~)0 23 Binoxide of Zinc-methyl. Dinitro-methylate nitrogen of zinc. Zinc-ethyl. Dinitro-etbylate of zinc. It will be perceived that these reactions are the exact analogues of the one already mentioned in the sodium and potassium series where carbonic acid treated with sodiurnemethyl and sodium-ethyl forms acetic and propionic acids. fa fact dinitro-methylic and dinitro-ethylic acids may be regarded as the analogues of acetic and propionic acid respectively ;the nitrogen here sustain- ing a biatoxnic character and replacing an equivalent amount of carbon.With Sulphnrous Acid.? Sulphurous acid. Zinc-methyl. Ahthy1odithionate of zinc. *Frankland Phil. Trans. 1857 p. 59. I-Hobson Chem. SOC. Qu. J. x 55 and 243. FRANKLAND ON ORGANO-METALLIC BODIES. 197 3(S,04) 3-Zinc-e thyl. Ethylodithionate of Line. With Terchloride of Phosphorus.* CiZnCl Zinc-methyl. Trimethylphosphine 6ZnC1 Zinc-ethyl. Triethylphosphine. There is no apparent obstacle to this reaction being pushed to its extreme limit in the case of pentatomic bodies such as phos- phorus arsenic or antimony. Mi. Buckton has rgcently at- tempted this in the case of antimony; but although evidence of the existence of a pentethide of antimony was obtained the body could not be isolated and its composition satisfactorily fixed.The great stability of the triatomic compounds of these bodies will probably present considerable disculty in the way of obtaining pentatomic compounds of an exclusively positive character such bodies being doubtless easily resolved into the more stable group-ings represented in the following equation Antimonic ethide. Triethyls tib ine. Ethyl. Whilst on the one hand organo-zinc compounds are thus capable of effecting the substitution of their positive organic group for negative elements they can on the other hand in certain cases replace hydrogen by zinc forming for instance with ammonia and its homologues a series of zincamides In this direction the following reactions have been recorded.? *Hofmann and Cahours Phil.Trans. for 1857,p. 578 j-Frankland Proc. of Royal SOC. viii 502. 198 FRANKLAND ON ORGANO-METALLIC BODIES. Zinc-ethyl. Ammonia. Zincamide. Hydride of ethyl. Zinc ethyl. Aniline. Zincphenylimide. Hydride of ethyl. -Zinc-ethyl. Diethylamine. Diethyl-zincamide. Hydride of ethyl. Zinc-ethyl. Oxamide Zincosimide. Hydride of ethyl. Zinc-ethyl. Acetamide. Binc-acetimide. Hydride of ethyl. Of the same nature apparently is the reaction between zinc-ethyl and acetic anhydride.* The members of the zinc-series unite with neutral salts to form compounds which have been but little examined.The following however are known :t Dinitromethylate of zinc and 0 + Zn '2"3 zinc-methyl iC2H3 Dinitroethylate of zinc and zinc-ethyl * When zinc-ethyl is added to acetic anhydride torrents of pure hydride of et.hyl are evolved ; the other product of the reaction has not been examined. Frankland Phil. Trans. 1857 p. 59. FRANKLAND ON ORGAPTO-METALLIC BODIES. 199 Finally it has been observed that zinc-methyl when generated in contact with methylic or vinic ether combines with these bodies forming* Methylatc of zinc-methyl 2(Zn jc2H3) + 2Eti 0 tC2H3 Ethylate of zinc-methyl 2 Cadmium 8eries.t-Only one member of this series is know& and that very imperfectly. So far as its properties are made out they appear to be perfectly analogous to those of the zinc compounds.Tin 8eries.f-A large number of organo-metallic bodies con-taining tin have been described. The existence of the following may be considered as clearly established a. Stannous compounds. Stannous methide or stanmethyl Sn {Ezgz Stannous ethide or stanethyl b. Sesqui-compounds. Sesquinzethide of tin Sesquiethide of tin Dimethiodide of tin Sn {ggi I Diethiodide of tin * Frankland Phil. Trans. 1859 p. 412. I. Wanklyn Chem. Soc. Qu. J. ix 193. $ Frankland Phil. Trans. 1852 p. 417 and Phil. Trans. 1859,~.401. Cahoure et Riche Compt. rend. xxxv 91 and xxxvi 1001. Lowig Ann. Ch. Pham. lxxxiv 3C8. A. Orimm Ann. Ch. Pharm xcii 383 Buckton Phil. Trans. for 1859 p. 423. Cahours Ann.Ch. Phya. lviii 22. 200 FRANKLAND ON ORGANO-METALLIC BODIES. E. Stannic compounds. Stannic methide Stannic ethide Stannic ethy lome thid e Stannic-ethylo-trimethide Stannic iodo-trimethide Stannic iodo-triethide Stanniv iodo-dimethide atannic iodo-diethide It is scarcely necessary to Qbserve that the iodine in the above compounds admits of replacement by any salt-forming radical and also by oxygen or sulphur Stannous compou7?ds are oily liquids soluble in alcohol and ether but insoluble in water and possessing a pungent odour. They cannot be distilled without decomposition being resolved FRANKLAND ON ORGAN0 -METALLIC BODIES. 201 into stannic compounds and metallic tin. They are in a state of partial chemical saturation only and therefore perform the part of radicals combining directly with chlorine oxygen &c.and forming well-marked bodies of great stability. Stannouv compoimda are bistomic and unite directly with free oxygen chlorine &c. to produce bodies of the stannie form. Thus stannous ethide forms with oxygen stannic oxydiethide. Stannous ethide. Stannic oxydiethide. Stannous cornpounds have never yet been observed to play a uniatomic part. No sesqixi-compound has been directly formed from n stannous body; the latter under the influence of iodine oxygen &c. seems to pass at once into the starlnic form. It must be remarked however that no direct experiments have been made with a view of revealing any uniatomic attribute which may attach to stannous compounds.Sesqui-compoundsof the form Sn R + have hitherto been very iR+ little examined. They are oily liquids uniting directly with nega- tive radicals forming an extensive series of compounds belonging to the stannic class a considerable number. of which have been studied. The following examples will serve to show the mode in which sesqui-compounds of this form pass into bodies of the stannic class Sesquiethide of tin. Stannic iodotriethide. Staanic iodotriethide. Stannic iododiethide. Iodide of ethyl. 202 FBAX'KLAND ON ORGAKO-NJ3TALLIC BODIES. No reduction of a sesqui-compound to a stannous compound has yet been effected although it can scarcely be doubted that an aqueous solution of diethiodide of tin for instance if treated with zinc would yield stannous ethide.On the other hand stannic ethide or methide in contact with iodine is transformed into a sesqui-compound vie. diethiodide of tin C4H5 CP5 2:; I Sn -j-1 = sn21c,LIs + 2~2~31 C,H Stannic ethylo-dimethide. Diethiodide of tin Iodide of methyl. Sesqui-compounds of the form Sn fgI are very little known. -b-In fact the diethiodide of tin the production of which from stannic ethyiodimethide has just been mentioned is the only one known with certainty. It is a colourless mobile liquid boiling with partial decomposition at 208" C. and possessing a most insupportable odour resembling essential oil of mustard. Heated with excess of iodine it is transformed into stanuic iododiethide Diethiodide of tin.Stannic iododi ethide. Stannic compounds of the form. Sn (%i are colourless mobile liquids possessing a slight ethereal odour. They are volatile without decomposition and are very stable. Being in the con-dition of chemical saturation they are incapable of direct com-bination. No body can act upon them without expelling one or more equivalents of positive radical. Thus when heated with hydrochloric acid stannic ethide yields stannic chlorotriethide and hydride of ethyl Stmnic ethide. Strtnnic chlorotriethide. Hydride of ethyl. FRANKLAND ON ORGANO-METALLIC BODIES. 203 With two equivalents of iodine the reaction is C*HS @; + 1, Sa = sn2{c4~5 '4:s) C4H5 + I Stannic ethide. Stannic iodotriethide.Iodide of ethyl. ,4nd with four equivalents of iodine Stannic ethide. Stsnnic iododiethide. Iodide of ethyl. Stanuic compounds of the form Sn {iI commonly called R-compounds of sesquistanethyl have been comparatively well studied. The oxides are in the anhydrous condition volatile limpid oily liquids which readily unite with water forming crystalline hydrates which have a powerful alkaline reaction and neutralize the strongest acids forming an extensive series of salts. These salts are almost all soluble in water readily crystallizable and of a very pungent odour. The stannic iodotriethide and the stannic triethylosulphate may be adduced as examples of the halo'id and oxysalts respectively Stannic iodotriethide I Stannic triethylosulphate Stannic compounds of the form Sn G'have also been very R- completely investigated.The oxides are white amorphous powders insoluble in water alcohol and ether. They dissolve in hydro-chloric hydriodic and hydrobromic acids forming colourless and 204 FRANKLAND ON ORGANO-NETALLIC BODIES. inodorous salts which crystallize in fine prisms. Most of the oxysalts can also be obtained in the crystalline form either from aqueous or alcoholic solutions. The iodide and sulphate of stannic diethide which may be regarded as representatives of the haloid and oxysalts have the following formuke Stannic ethylodisulphate Sn Stannic iododiethide I Stannic compounds of this form are readilyreduced to stannous compxmds; thus when a piece of zinc is plunged into a solution of stannic chlorodiethide stannous ethide is produced Stannic chlorodiethide.Stannous ethide. BISMUTH SsR;rEs.*-The following bodies belonging to this series have been described 1. Bismuthous ethide Bi -fCg5 2 Bisrnu thous dichlor et hide c 3. Bismuthous di-iodoc thide Bi CI Bi -!'f4? 4.Bismuthons dioxyethide * Breed Ann. Ch. Pharm. lxxxii 106; Diinhaupt Ann. Ch. Pharm. xcii 371. FKANKLAND ON ORGAXO-RIETALLIC BODIES 205 5. Double compound of bis-muthous aulphide with bismut hic sulp hot rie th ide These bodies have as yet been but very imperfectly investigated. Bismuthous triethide is a colourless or slightly yellow mobile liquid having an unpleasaat odour like that of stibethine.Exposed to the air it gives off dense yellow fumes inflames spontaneously and finally explodes. It is very instable begins to decompose at 50' or 6Q0C. and explodes violently when heated to 150' C. a temperature still below its boiling point. No direct compound of this body has yet been obtained; it behaves like a chemically saturated substance and when slowly oxidized in contact with water yields alcohol and hydrated oxide of bismuth Bismuthous ethide. Alcohol. When an alcoholic solution of bichloride of mercury is added to an alcoholic solution of bismuthous ethide mercuric ethocliloride crystallizes out whilst biamuthous dichlorethide remains in solu-tion + 2HgC1 = BiiCg5 + 2HgfCg6 c1 Bismuthous Bismuthous 1cIercuric ethide.dichlorethide. chlorethide From the bismuthous dichlorethide the diiodide and dioxyethide are prepared by double decomposition whilst the simtltltaneous action of sulphuretted hydrogen water bismuthous ethide and atmospheric oxygen is said to produce the double compound of bisrnuthous sulphide and bismuthic sulphotriethide. LEADSERms.*--The follotving bodies only are known the ethyl group alone having been explored * Lowig Ann. Ch.Pharm. lxxxviii 3iS; Bucliton Phil. Trans. 1859 p. 417. 206 FRANHLAND ON ORGASO-METALLIC BODIES. Didurnbic triethide I Plumbic oxytriethide Plumbic chlorotriethide Plumbic triethylosulphate Plumbic ethide The existence of the first of these bodies cannot be said to be clearly established; but by the action of an alloy of sodium and lead upon iodide of ethyl a colourless mobile volatile liquid is obtained which when dissolved in alcohol or ether and exposed to the air forms plumbic oxytriethide a body which is however more readily obtained by the decomposition of the chloride wit1 oxide of silver Pltimbic chlorotriethide Plumbic oxytriethide.Plumbic ethide is a colourless limpid fluid soluble in ether but insoluble in water and possessing a faint odour. It is not acted upon by oxygen at ordinary temperatures but chlorine bromine and iodine act violently upon it. Plumbic ethide belongs to the class of saturated bodies and is consequently incapable of forming compounds. When it is treated with hydrochloric acid hydride of ethyl separates and plumbic chloro-triethide is formed FRANETAAND ON ORGANO-METALTJC BODIES.Plumbic Plumbic Hydride of ethide. chlorotriethide. ethyl. From plumbic chloro-triethide the sulphates and other salts can be prepared by double decomposition. These salts may also be obtained still more readily from the oxide which is a crystalline volatile pungent body possessing a powerful alkaline reaction and attracting carbonic acid from the air. MERCURIC SEftIEs.*-This series is confined to bodies of the mercuric type no organo-mercurous compound having been yet produced. It comprises the following members Mercuric methiodide Mercuric methhydrate Xercuric methonitrate Mercuric methide Mercuric ethiodide Mercuric ethohydrate Mercuric ethonitrate Mercuric ethide Mercuric ethylornethide Hereuric methide and mercuric ethide are colourless ethereal volatile liquids insoluble in water but insoluble in alcohol and * Frankland Phil.Trans. 1852 p. 436 and Phil. Trans. 1859 p. 409 ; Diin-haupt Ann. Ch. Pharm. xcii 3’71;Strecker Ann. Ch. Pharm. xcii 57; Buokton Phil. Trans. 1858 p. 163 and 1859 p. 41’7. 208 FRANKLAND OX ORGAiYO-METALLIC BODIES. ether and possessing great stability. They are in a state of maximum saturation and cannot therefore unite with any other body without the displacement of an equivalent of positive radical. Thus with bromine mercuric etliide gives bromide of ethyl and mercuric ethylobromide ~- Mercuric 1\1e rcuric Bromide of ethide.e thy lobromide. ethyl. With hydrated sulphuric acid the action is __________ -~ Mercuric Mercuric Hjdride of ethide. ethosulphate. ethyl. Mercuric methide possesses the highest specific gravity of any known non-metallic liquid (3*069) Glass consequently floats upon its surface. Brought in contact with mercuric iodide mercuric methide and mercuric ethide are converted respectively into rricrcuric methiodide and mercuric ethiodide -Mercuric methide. 3l ercuric methiodide. Nercuric ethide. Mercuric ethiodide. The reaction with mercuric chloride is exactly analogous. The hydrates of mercuric methoxide and mercuric ethoxide are caustic allialine bases capable of expelling ammonia from its salts and behaving in a manner similar to the corresponding uniatomic compounds of tin and lead.The remaining mercury-compounds which may be considered as derivatives of these two bodies are represented in the above list by the iodides and nitrates they generally crystallize very readily and with the exception of the haloid compounds are soluble in water. When their aqueous solutions are treated with zinc they are decomposed the zinc becomes amalgamated and gaseous hydrides of the positive radicals are evolved. It is highly probable that there are two FRANKLAND ON ORGANO-METALLIC BODIES. 209 stages in this reaction organo-zinc compounds being first formed and then decomposed by contact with water ;thus with mercuric methiodide-Mercuric methiodide. Zinc-methyl and then Zinc-methyl.Water. Hydride of methyl. This view of the reaction is confirmed by the fact that when zinc acts upon mercuric methiodide at 150' C. zinc-methyl is produced. When one of the above iodides or the corresponding chloride or bromide is treated with an organo-zinc compound the negative element becomes replaced by the alcohol-radical of the zinc-compound ; thus when mercuric methiodide is treated with zinc-methyl mercuric methide is produced. And it is believed that by acting upon mercuric ethochloride with zinc-methyl mercuric ethylornethide is produced Mercuric ethochloride. Zinc-methyl. Mercuric ethylornethide. but this body has not yet been obtained in a state of purity; distillation gradually resolves it into mercuric methide and mercuric ethide Mercuric ethylornethide.Nercuric methide. Mercuric ethide. ANT~MONY SERms.*-This important series of organo-metallic bodies contains a greater number and variety of compounds than any other with the exception of the arsenic series. The remark-able polyatomic character of antimony and arsenic not only renders the possible number of their orgauo-compounds very * LSwig Ann. Ch. Pharm. lxxv 315 327; Landolt Ann. Ch. Pharm, lxxviii 91 ; Buckton Chem. Soo. Qu. J. xiii 115; Hofmann ibid xi 316. VOL. XIII. P 210 FRANKLAND ON ORGANO-METALLIC BODIES. large but the variation in the proportions of the positive and negative molecules gives an extremely wide range to their chemical character extending as it does from highly caustic bases on the one hand to powerful bibasic acids on the other.The following are the principal compounds belonging to tbis series Trimethylstibine Antimonic trimethoxide Ant imonic trimethochloride Iodide of tetramethylstibonium or antirnonic tetramethiodide \ Hy&ate of tetramethylstibonium or antimonic tetramethylhydrate Antirnonic trimethosulphate Triethy lstibine Antjmonic triethoxide FRANKLAND ON ORGANO-METALLIC BODIES. 211 Antimonk triethochloride Iodide of tetrethylstibonium or antirnonic tetramet hiodide Iodide of methylo-triethylstiboaium Sb or ant im onic triet hornethi0dide Hydrate of te tr ethylstibonium or antimonic tetrethylbydrate C*% C4H5 Antimonk triethodpht e Sb C4H5 i Sulphnte of tetrethylstibonium Sb or antimonic tetrethylsulphate Antimonic triethoxiodide Sb C4H5 r: Triam ylstibine P2 212 FRAXKLAND ON ORGAXO-BIETALLTC BODIES.An timonic triam ylchloride Antimonic triamylnitrate It is remarkable that we have as yet no decisive evidence in this series of the existence of a compound corresponding to cacodyl. It is true that such a body has been described under the name of stibbiamyl but subsequent experiments have failed to confirm its existence. Amongst organo-antimony compounds therefore the most simple form is Sb R+ Bodies of this form -K are the analogues of ammonia and need not be here described (2 since their history and also that of bodies having the form Sb R+ 12 will be found in a discourse upon u Ammonia and its Derivatives," delivered to this Society June 17th 1858 by Dr.Hofmann." The only bodies therefore of this series requiring notice here are those of the form Sb R + and their derivatives. When the [:! R- two atoms of R-are oxygen these compounds constitute what may be termed biacid antimony bases. They are formed either by the direct union of the stibamines (Sb R+ with oxygen. {;I) B+ + 0 = Sb[tz 0 0 * See vol. xi p. 252 of this Journal. FRANKLAND ON ORG-4NO-METALLIC BODIES. 213 or by the decomposition of the corresponding haloid compounds by means of potash thus-Sb R + 2KO = Sb R+ + 2KCl [El [;: C1 The stibarnines although in other respects the perfect analogues of the nitramines here evidently exhibit a much more highly positive character uniting with oxygen so energetically as to be spontaneously inflammable in the lower portion of the series.The biacid antimony bases are colourless transparent amor-phous and tenacious bodies; the ethyl base is easily soluble in water and alcohol but somewhat less soluble in ether. They possess a bitter taste are non-volatile and do not suffer any change when exposed to the air. Treated with potassium. they are reduced to stibamines R+ + 2K = Sb(B+ + 2KO R+ Fuming nitric acid decomposes the biacid bases with ignition; but when they are treated with dilute nitric or other acid the respec- tive biacid salts are produced. The oxysalts are soluble in water or alcohol; most of them crystallise without much difficnlty as do also the antimonic biniodides ;but antimonic triethobromide and triethochloride are liquids not volatile without decomposition insoluble in water but soluble in alcohol and ether.The existence of antimonic triethoxiodide has been recently proved by Strecker. It had previously been regarded by Merck as a protoiodide of stibethiue (Sb (C4H,J31). ARSENICSERIEs.*-This series is perhaps the most important and interesting amongst organo-metallic bodies ; it contains the first discovered organo-metal caoodyl the classical investigation of * Cadet (1760) MBm. de Nath. et Phys. de Savants Btrang. iii 633; Thenard Ann. Ch. lii 54; Bunsen Ann. Ch. Pharm. xxiv 27; xxvii 1; xlii 14; xlvi 1 ; Frankland Ch.Soc Qu. J. ii 299 ; Cahours et niche Compt. rend. xxxvi 1001; Landolt Ann. Ch. Pharm. lxxxix 301; Hofmann Chem. SOC.Qu. J. xi 316. Baeyr Ann. Ch. Phann. cvii 257 j cv. 265. 214 FRANKLAND ON ORGANO-METALLIC BODIES. which by Bunsen not only imparts a completeness to our know-ledge of this series but has afforded the clue to the successful interpretation of many phenomena met with in other analogous families. It will be convenient to divide its very numerous members into three groups. A. Csrgano-arsenical compounds of the type As is B. Organo-arsenical compounds of the type As g C. Organo-arsenical compounds of the type As All arsenical compounds permit of being arranged under these three types. The following are the principal bodies already investigated A.Organo-arsenical Compounds of the Type As i Cacodyl Ethylic cacodyl As {ZE Propylic cacodyl As (2;;? Butylic cacodyl As {2::? B. Organo-arsenical Compounds of the Type As R r3.E Oxide of cacodyl As C,H Sulphide of cacodyl Chloride of camdyl \ FEANKLAND ON ORGANO-METALLIC BODIES. 215 Chloride of cacoplatyl As Arsenious dioxymethide As p?3 0 Arsenious disulphornethide As S -rr3 Arsenious dichloromethide As lc2Ef Trime thy larsine Arsenious diethiodide Triethylarsine C. Organo-arsenical Compounds of the Type As \E This group may be conveniently divided into four families or sub-types viz. a. Bodies of the form As 6' and their derivatives. R- 6.Bodies of the form As and their derivatives. R-c. Bodies of the form As and their derivatives. 216 F.GK"LAND ON ORGANO-METALLIC BODIES. d. Bodies of the form As R+ a. Sub-type R-As p R- C2H3 0 Monomethylarsenio acid 0 0 As 0 i Monomethylarseniates Arsenic diaxydichlormethide As Arsenic tetraohtormethide C1 CI 6. Sub-type Cacodylic Acid FRANKLAND ON OBGANO-METALLTC BODIES. Cacod ylates Sulphocacod ylic acid Sulphocacodylates Terchloride of cacodyl As Ethyl-cacodylic acid AS E:thy 1- cacodylates Arseiiic triethQxide 218 FRANKLAND ON ORGANO-METALLIC BODIES. Arsenic triethosulphate Arsenic triethosulphide As C,H, r: Arsenic triethochloride R+ R+ d.Bodies of the form As[ R, R- C2H3 VI3 Oxide of tetr ameth ylarsonium As {c2H3 or arsenic tetramethoxide C2H Iodide of tetramethylarsonium or arsenic tetramethiodide Oxide of dimethyl-diethylarsonium As or arsenic dimethyl-diethyloxide FRANKLAND ON ORGANO-NETALLIC BODIES. 219 Iodide of dimethyl-diethylarsonium or arsenic dimethyl-diethyliodide Nitrate of dime th yl-die thy1 arsonium or arsenic di met hy1 -diet h ylni trat e Oxide of tetrethylarsonium or arsenic tetrethoxide Sulphate of tetrethylarsoniurn or arsenic tetrethylsulphate Chloride of tetrethylarsonium or arsenic tetrethylchloride Iodide of dimethyl-diamylarsonium or arsenic diamyliodide The organo-arsenical compounds belonging to the type As contain only positive radicals.They are volatile poisonous liquids insoluble in water but very soluble in alcohol and ether and possessing an insupportable odour. The lower members of the family are spontaneously inflammable whilst the higher ones also rapidly oxidise in air. They unite with negative elements with great energy manifesting in their combinations either a uniatomic or a teratomic character and producing bodies either of the form As R+ or As R-. Thus cacodyl fonns with g' 2 [.,I chlorine chloride of cacodyl and terchloride of cacodyl. 220 FEANKLAND ON ORGANO-METSLLIC BODIES. Caeodyl. Chloride of eacodyl. {:;2 + i'4 AS ~1 = AS ci Cacodyl Terchloride of cacodyl. Nethylic cacodyl boils at 170"C. and ethylic cacodyl between 185" and 190" C.Heated to 400' C. cacodyl splits up into metallic arsenic hydride of methyl and olefiant gas Cacodyl. Hydride of methyl. Olefiant gas. Bodies of this type can be regenerated by reducing agents from many of their uniatomic compounds ; thus chloride of cacodyl and metallic zinc give cacodyl and chloride of zinc Chloride of cacodyl. Cacody1. Organo-arsenical compounds of the type As forms viz. (2) As {E: R-Those belonging to the first are termed arsines and are the analogues of ammonia ; but like the corresponding antimony compounds in addition to their alkaloid function they have the power of combining with two negative atoms forming bodies of 1: the sub-type As ( R + . Thus triethglarsine combines with oxygen R-R-to form arsenic dioxytriethide.The lower members of the type FRAINKLAXD ON OEGANO-METALLIC BODIES 221 possess this property to such an extent as to render them spon- taneously imflammable in air. Compounds belonging to the second of the above forms are produced by the direct combination of the cacodyls with negative elements the oxides are bases of comparatively feeble power slowly combining with two additional equivalents of oxygen to form acids. Thus oxide of cacodyl by exposure to air slowly passes into cacodylic acid As p2 0 02 Oxide af cacodyl. Cacodylic acid The chlorine bromine and iodine compounds of the form we are now considering are volatile neutral bodies which may be regarded as the haloid salts of cacodyl.Heated in contact with bichloride of platinum the chloride of cacodyl presents an inte- resting re-action; two equivalents of hydrogen in the cacodyl become replaced by a biatomic molecule of platinum producing chloride of cacoplatyl. -r2:AS C2H3 + PtCl = (C23%,AS C,Bt 131 c1 + 2HC1 Chloride of cacodyl. Chloride of cacoplatyl. Cacoplatyl forms a series of compounds analogous to those of cacodyl. The only compounds of the third form yet known belong to the methylic group. Arsenious dioxymethide is a crystalline body of a neutral character soluble in water alcohol and ether un- changed by exposure to air but transformed by distillation with hydrate of potash into arsenious acid and oxide of cacodyl 2 AS-0 = AsO + As C2H3 I:”” r3 Arsenious dioxymethide.Oxide of cacodyl. Hydrochloric acid coiiverts it into arsenious dichlormethide C2H3 c2H3 As{ 0 +2HCl = As{ C1 c1 + 0, 0 4 r,,,’ dioxymethide. Arsenioiis dichlormethide. -Q 222 FRAN KLAND ON ORGANO-METALLlC BODIES. Hydrobromic and hydriodic acids produce a perfectly analogous change whilst sulphuretted hydrogen tranforms it into arsenious disulphomethide. The chloric compound can also be formed by heating arsenic trichlormethide to 50’ 1::::: C. As + “.3> As Cl ( Cl Arsenic Arsenious Chloride of trichlormethide. dichlormethide. methyl. The chlorine bromine and iodine compounds are neutral bodies of considerable stability; the two former are liquid the latter solid and crystalline.By the action of chlorine or oxidising agents they R+ R-are transformed iuto bodies of the form As Organo-arsenical compounds have been more thoroughly investi- E gated in the direction of the type As kR than in any other; conse- quently me find therJe bodies rather numerously represented E 1 especially under the subtype As R +. As the latter bodies in + (R -however are the strict analogues of the compounds of ammonium their chemical relations will be found fully described in Dr. Hof-mann’s discourse before alluded to R+ R -has only yet been explored in the rnethylic Sub-type As {;1 -group. The oxygen-compound constitutes anhydrous monomethyl- arsenic acid a direct derivative from arsenious dioxymethide PRANKLAND ON ORGANO-METALLIC BODIES.223 + 2Ago = As 0 Arsenious dioxymethide. Monomethylarsenic acid. This acid is bibasic forming stable and well defined crystallisable salts the formulz of which are represented by the general ex- pression The chlorine compound is exceedingly unstable ;it may however be formed at -lO°C. but is transformed at OOC into arsenious chloride and chloride of methyl Arsenic te trachlormethide Chloride of methyl. Arsenic dioxydichlormethide is a somewhat more stable body formed by the direct union of chlorine with arsenious dioxymethide. + C1 = As 0 Cl ArEenious dioxyrnethide. Arsenic dioxydichlormethide. Nevertheless even this compound readily decomposes with evolution of chloride of methyl Sub-type As H -The oxygen-compounds are feeble mono-:E ! It- basic acids of which cacodylic acid may be regarded as the repre- IR + sentative They are derived from the bodies As R + by direct io 224 FRANKLAND ON ORGA?&-O-SIETALLICBObIES.oxidation as already described. Cacodylic acid IS remarkable for its stability ;neither firming nitric acid nor a mixture of sulphuric ; and chromic acids attack it even at the boiling point and it may be heated to 200" C. without alteration. Although it is soluble in water and contains upward of 54 per cent. of arsenic yet it is not in the least poisonous. Several agents reduce cacodylic acid to the arsenious or even to the diatomic form. Thus phosphorous acid transforms it into cacodyl C2H3P2Z3 +2Asi 0 3P-p 0 = 2 As (&3 c 14 23 4- 3P0 0 Cacodylic acid.Cacody1. Zinc also produces the same result. Hydriodic acid gas con- verts cacodylic acid into arsenious dimethiodide (3% CP3 0 + 3HI = As + I + 380 0 0 The acid character of this body is so slightly marked as to render it capable of forming compounds in which it appears to play the part of a base. Thus with hydrofluoric hydrochloric and hydrobromic acids it forms the following compounds Hydrobromate of cacodylic acid As H 0 The hydrohromate reacts perfectly neutral. The cacod ylates have the formula 0 Lo2 Sulphocacodylic acid has not yet been isolated but its salts pre-sent the same relations to those of cacodylic acid as salts of sulphur-acids generally bear to those of oxyacids.Their formula is Sub-type As R + has hitherto been very little explored so 111 -(R -far its it is known but its members bear so close a resemblance to their analogues in the aritimony-series as to reqaire no further notice. SERIES.* The close rclatiorrs of tellixrinni to sulphiir TELLTTRIUM and selenium place the bodies of this series in the same position with regard to the sulphides and selenides of the alcohol-radicals as the antimony aiid arsenic series stand in relation to the corre-sponding compounds of phosphorus and nitrogen. The following bodies belonging to this series are knoim Tellurium methyl Telluroiis clirnethoxirle Telluroiis methoxychloride Cl * Wdhler Ann. Ch. Pharm. xxxv 112 lxxxiv 69 Mallet Ann.Ch. Pharm. lxxix 223 ; Wdhl er and Dean Ann. Ch. Pharm. xciii 233. VOL. XJII 9. 226 B'RANKLAND ON ORGAKO-METALLIC I?OI)IEP. Tellurium-ethyl Tellurous diethoxide C4H* Tellurous diethosulphide Te p:5 S Acid tellurous diethosulphate C*% Te {%: so4 Tellurous diethochloriclc Tellurous diethoxychloride ,,.i"": Tellurous diethiodide I Tellurium-amyl The compounds of the alcohol-radicals with tellurium are vola- tile liquids of most unbearable odour. They orridise readily in contact with air forming tbe respective oxides. Tellurium-amyl has not yet been obtained in a state of purity. The oxides of these bodies are powerful bases expelling ammonia from its salts and attracting carbonic acid from the air.They form salts of considerable stability which as well as the oxides themselves yield the original organo-tellurium compounds when ,treated with sulphurous acid FRANKLAND ON ORGANO-METALLIC BODIES. 227 Tellurous diethoxide. Tellurium ethyl. Constitution and Theoretical Importanceof Organo-metallic Bodies. In the year 1852*,at a time when comparatively little progress had been made in the investigation of organo-metallic bodies I ventured to propose a view of their constitution which further research has cotnpletely confirmed. According to this view the organo-metallic bodies are constructed upon the types of the inorganic chlorides sulphides oxides &c. of the respective metals which they contain the chlorine oxygen stdphur &c.being replaced in equivalent proportion and step by step by the alcohol- radicals. A reference to the formuh of organo-potassium sodium magnesium zinc and cadmium compounds given above shows that they are all formed upon the models of the protochlorides of these metals ; the general type being {: 3% In like manner organo-aluminium compounds are formed upon the type of the sesquichloride of that metal Organo-tin compounds are represented by the three chlorides of tin The compounds of the bismuth-seyies me represented by the terchloride of bismuth and by bismuthic acid 1: 0 Bi * Phil. Trsna. for 1852 p. 438. Organo-lcad comporxnds :w :wrm(yd under the tppcs of sesqiiioxide and peroxide of lead 0 Pb {’:0 P+ 0 The mercury-series are all mouldcd upoii the type of the bichloride The arsenic and antimony swies have for their types the following inorganic compounds Sb fC1 , C1 ZCI The inorganic models for the tellurinm series are ctil&le of telliirium and telluroixs acid Occasionally an abnormal componnd has made its appear-ance such as ethostibilic acid (Sb (C El,) 0,) or iodide of triethylstibinc (Sb (C H5)3J); but farther research has invariably demonstrated the incorrectiiess of SUC~ forrnulze and the conformity of the bodies with the normal inorganic types.Indeed this law may now be regarded as sufficiently established to be applicable to the control of the formulce of new organo-metallic bodies. From the point of view thus afforded it is interesting to watch the effect of the substitution in metallic compounds of basjlous or positive for chlorous or negative radicals.Such a substitution affords striking evidence of the dependence of the chemical character of a colapound upon that of each individual constituent. The highly poly atomic metals such as arsenic and antimony exhibit this dependence in the most conclusive manner. Thus tribasic arsenic acid by the substitution of an equivalent of methyl for oxygen yields the bibasic monomethyl-arsenic acid a well defined acid of considerable energy though inferior in chlorous power to arsenic acid. The like substitution of a second equivalent of rnethyl for oxygen reduces the chlorous character of the body to the com-paratively feeble condition in which we find it in cacodylic acid which is incapable of forming an ammonia-salt.A similar substi- tution for the third time overpowers the acid attribute of the compound altogether and we now have a feeble biacid base the arsenic dioxymethide which again by the exchange of a fourth atom of oxygen for methyl is transformed into the oxide of tetra-methylwsonium a base of such energy as to be comparable with the caustic alkalies themselves. The behaviour of the organo-metallic bodies teaches a doctrine which affects chemical conipounds in general and which may be called the doctrine of atomic saturation ;each element is capable of combining with a certain limited number of atoms ;and this number can never be exceeded although the energy of its affinities may have been increased by combination up to this point.Thus zinc appears to attain its atomic sattzratioa by uniting with only one atom of another body; in other words it is uniatomic consequently the zinc compounds of’the alcohol- radicals not wit tist anding their intense affinities are incapable of direct union with other bodies. The action of chlorous elements upon them is apparently one of substi-tution not of combination. Polyatornic metals exhibit the same phenomenon. A Gouble atom of tin cannot combine with more than four atoms ; a siiigle atom of arsenic or antimony with more than five atoms of other bodies ; but in the combinations of poly- atomic metals me frequently notice from the lowest to the liiglirst coinpound one or more intermediate points of exalted stability ; thus antimony has a teratomic stage of comparative stability ; nitrogen *phosphorus aiid arsenic whilst exhibiting a similar ter- atomic stage have also a biatomic one tliough of greatly inferior stability ; whilst the existence of protoxide of nitrogen renders it more than probable that nitrogen has a third and uniatomic stage.Inbodies possessing at least one stage of stability below saturation and in which all the atoms united with the yolyatomic element are of the same kind the stage of maximum stability is very rarely that of saturation. Tlms in niirogen arsenic and bismuth com-pounds of the kind just Ynentioncd the stage of maximum stability is decidedly the teratomic one; in antimonial cornpounds of a similar nature the teratomic is also though less decidedly the stage of maximum stability whilst in pliosphorous compounds the 230 FRANKLAND ON 0RGANO-R.lETALLIC BODIES points of maximum stability and of saturation generally coincide 'When however the atoms united with the polyatomic element are not of the same kind then the stage of maximum stability usually coincides with that of saturation.Thus the binoxide or bichloride of triethylarsine or triethylstibine are more stable than triethylarsine or triethylstibine themselves ;hut this pentatomic stability reaches its climax in arsonium stibonium and phos-phonium compounds as it does also in the corresponding com-pounds of nitrogen although the latter element exhibits a much stronger tendency towards universal teratomic stability than its chemical associates.In polyatomic organo-metallic bodies it is remarkable that with few exceptious the positive hydrocarbons hold their position much mctre tenaciously than the associated negative constituents ; ar?d we thus frequently find the former accompanying the metal through a vast number of compounds. Hence the group formed by the metal and positive hydrocarbons has come to be regarded as a compound radical. Thus cacodyl is conceived to be the radical of the whole series of cacodyl compounds. Rut however great may be the convenience of this mode of viewing organo-metallic corn- pounds and the same mode has notoriously been extended to nearly all organic bodies it must not be forgotten that it is a purely artificial distinction which has no real existence either in the case of organo-metallic bodies or as 1 shall endeavour to show in that of organic bodies in general.A close examination of the habits of the so-called organo-metallic radicals shows clearly that their atomic power depends upon their position with regard to the stages of stability and maximum satixration ;thus they are uniatomic when the number of positive groups is one less than that required to reach either the maximum saturation of the metal or a lower stage of stability. Cacodgl and tetramethyl-arsonium for instance are uniatomic radicals because they are respectively one atom short of the stage of stability and of maximtim saturation Uniatomic stage.Stage of stability. As C,H, -r Cacodyl. Chloride of cacodyl. FRANKLAND ON ORGANO-NETALLIC BODIES. 231 Uniatomic stage. 8f?gcof maviniuln saturation. - ____.-_ Tetramethylarsonium. Chloride of tetramethylarsonium. It is obvious that a compound radical the number of whose positive atoms is below that of a stage of stability can have a double atomic character. Thixs cacodyl is sometimes uniatomic as in oxide of cacodyl ;and sometimes teratomic as in cacodylie acid. Again arsenio-monomethyl (AsC,H,) is biatornic in arsenious dioxymethide and quadratomic in monomrthylarsenic acid If these views of the constitution and character of organo-metallic bodies and their compounds be correct their application to the organic compourids of carbon becomes inevitable.Regarded from this point of view the double atom of carbon like that of tiu is quadratomic in perchloride of carbon and carbonic acid ~ C~i~ G{S0 Yerchloride of carbon. Carbonic acid. and biatomic ip protochloride of carbon and carbonic oxide (Q {E c2 c2 (0 Protochloride of carbon. Carbonic oxide. In other words the quadratomic stage in carbon-compounds is the stage of maximum saturation whilst the biatomic stage is one of exalted stability. If we substitute an atom of chlorine in per- chloride of carbon by one of ethyl we produce a body having the formula of trichlorhvdrin If now a second atom of chlorine be substituted by one of hydrogen we have a body exhibiting the composition of bichloride of propylene This view of the constitution of bichloride of propylene renders its relations to ally1 and glycerin compounds at once simple and intelligible.The substitution of a third atom of hydrogen gives the forinula whilst the substitution of tlic last atom of' chlorine by hydrogen yields hydride of propyl and its replacement by ethyl yields the so-called double radical ethylpropyl. It still remains for experiment to produce these bodies from perchloride of carbon and to show that they are identical with the known compounds possessing the same percentage composition.* If however 117e turn to the oxygen-compounds of carbon we are not entirely without experi- mental evidence of the correctness of this view ; since one atom of oxygen in carbonic acid has been replaced by ethyl with pro-duction of the body theoretically indicated namely propionic acid Could a second atom of oxygen be substituted by hydrogen we ought to produce propionic aldehyde * Such experiments are in progress but are not sofficiently advanced to be here quoted FRANKLAND ON OKGAKO-ME KALLIC BODIES.233 The replacement of a third &tornof oxygen by hydrogen would then yield propylic ether whilst the replacement of the last atom of oxygen by hydrogen should give rise to hydride of propyl and by uniatomic peroxide of hydrogen to propylic alcohol Hydride of propyl. Propylie alcohol. The glycols are also constructed upm the carbonic acid type Glycol.arid to the same type belongs also the teracid alcohol glycerin. Under the influence of iodide of phosphorus glycerin yields iodide of allyl -Glycerin. Iodide of allyl. Phosphoric acid Here we have a reduction from the carbonic acid to the car- bonic oxide type of precisely the same nature as that which occurs when cacodylic acid is reduced to oxide of cacodyl. Allylic compounds are therefare constructed upon the carbonic oxide type* 234 FRANKLAND ON 0RGANO-21 ETALLIC I%OI)IE3. Carbonic oxide. Iodide of allyl. Allylie alcohol. It would be easy greatly to extend this view of the constitution of organic carbon compounds; but the above examples are sufficient to indicate its geueral application somewhat more fully than 1 have previously done,* and more than this is not desirable until the hypothesis has been further supported by experimental results.In conclusion it is evident that this is only one mode of applying to organic compounds the law of chemical eornbination which I have endeavoured to deduce from the constitution and behaviour of organo-metallic bodies. Its application ought to be and will be found to be equally truthful in referring organic compounds containing hydrogen oxygen or nitrogen to the inorganic typical compounds of each of these elements. Thus for example we can represent alcohol lst as derived from carbonic acid Znd as derived from teroxide of hydrogen 3rd as derived from water In like manner nitrogen compounds and their analogues whilst derived from typical inorganic compounds of nitrogen are also * Ann.Oh. Pharm. ci 260; Proc. of Royal Inst. of Great Britain for 1858. It is highly remarkable that more than thirteen years ago when such analogies were of the most obscure kind the quick perception of Liebig led him to point out analogous relations between carbonic acid alcohol formic acid and marsh gas. See Ann. Ch. Pharm. Iviii 335.) FOSTEIt ON ACETOXYBENZAMIC ACID. true derivatives from the carbon types. Thus trimethylamine is correctly written as a derivative from carbonic acid Each of these modes of notation is equally correct; bat I conceive that a large number of those organic bodies which are usually formulated in accordance with the hydrogen water and hydrochloric acid models mould be much more usefully expressed upon the carbonic acid aud carbonic oxide types.The formulation of organic compounds is not a matter of indifference even to the chemical investigator; and hence every mode of expression founded upon broad chemical relations ought to have the preference over more purely artificial methods.