Page:Encyclopædia Britannica, Ninth Edition, v. 5.djvu/586

574 CHEMISTRY [ORGANIC. The action of slow oxidation upon the compounds of this family is shown in the following examples : Zn(C 2 H 5 ) 2 Zinc ethicle. Zn(C 2 H 5 ) 2 Zinc ethide. O = Zn(C 2 H 5 )(OC 2 H 5 ) Zinc etho-etliylate. 2 = Zn(OC 2 H 5 ) 2 . Zinc ethylate. Organo-boron compounds containing boron directly com bined with hydrocarbon radicles have been obtained by the aid of zinc methide and ethide : 2B(OC 2 H 5 ) 3 Triethyl borate. 3Zn(CH 3 ) 2 = 2B(CH 3 ) 3 Zinc methide. Boric met hide. 3Zn(OC 2 H 5 ) 2 . Zinc ethylate. Boric ethide has been prepared by an analogous reaction. Boric methide is a gas, and boric ethide a limpid liquid; both are spontaneously inflammable, burning in air with a green-tinted flame. They combine with ammonia form ing compounds of the formula NH 3 , BR 3 . Organo-silicon compounds are bodies in which carbon is replaced partially or entirely by silicon. Many of these are formed by means of zinc methide and its homologues : SiCl 4 + 2Zn(C 2 H 5 ) 2 = Si(C 2 H 5 ) 4 + 2ZaCl 2 . Silicic chloride. Zinc ethide. Silicic ethide. A large number of these compounds are now known. Their analogy to the carbon compounds will be seen from the following examples : Si(CH 3 ) 4 C(CH 3 ) 4 SiHCl 3 CHC1 3 . Silicic methide. Tetramethyl-methane. Silicon chloroform. Chloroform. H.SiO(OH) CH 3 .SiO(OH) C 2 H 5 .SiO(OH) SilicofoiTnic acid Siliconacetic acid. Siliconpropionic acid. H.CO(OH) CH 3 .CO(OH) C 2 H 5 .CO(OH) . Propionic acid. Formic acid. Acetic acid. XIII. AMINES. It has been previously otated that amines are derivatives of ammonia or its hydrate and haloid salts (p. 553), hydro gen being partially or entirely replaced by hydrocarbon radicles. Amines built on the type of NH 3 may arise from the replacement of hydrogen in NH 3 , N 2 H 6 , or N 3 H 9 , thus forming monamines, diamines, or triamines : H (R (H (R" NVH NJH.; *MH 2 H H H Ammonia (1 molecule). Monamine. Ammonia (2 molecules). Diamine. Similarly triamines are formed by replacement of H 3 by R ". Each of these groups of amines is further divisible into primary, secondary, and tertiary, according as one-third, two-thirds, or all the hydrogen of ammonia is replaced by hydrocarbon radicles. For example : R R R H Primary monamine. H ( R R" H Primary diamine. y Secondary inc. monamine 1 N 2 < !T>" R ~P K 2 (R" N-J R" 1 H (H Tertiary monamine. R" R" N r R" R" R" Secondary diamines. R" H, R " Tertiary diamines. R " R" Primary triamines. {R" ( R" R 3 NJR" R 3 ( R 3 Secondary triamines. R" R Tertiary triamines. Monamines containing C n H 2tt+1 mfoWes. The following are known : Primary, Methylamme Ethylamine N(C 2 H 5 )H 2 Propylamiiie N(C 3 H 7 )H 2 Butylamine N(C 4 H 9 )H 2 Am ylamine N(C 5 H n )H 2 Hexylamme N(C 6 H ]3 )H 2 Heptylamine N(C 7 H 15 )H 2 Octylamine N (C 8 H 17 )H 2 Nonylamine N(G,H 19 )H 2 Secondary. Dimethylamine N(CH 3 ) 2 H Methyl-ethyl- ) N , CH ,, p aminc |JN^H 3 KC 2 ri Diethylamine . . . N(C 2 H 5 ) 2 H Dipropylamine, N(C 3 H 7 ) 2 H Dibutylamine...N(C 4 H 8 ) 2 H Ethylamyl- ) Nfr .. amine j >M^ u B)m> Diamylamine ...N(C 5 H n ) 2 H Tertiary. Trimethylamine .................................... N(C 3 H) 3 Triethylamine ....................................... N(C 2 H 5 ) 3 Tripropylamine ..................................... N(C 8 H 7 ) 8 Tributylamine ....................................... N(C 4 H 9 ) 3 Triamy lauiine ...................................... N(C 6 H 11 ) 3 These amines are produced by the following methods : 1. By heating the haloid compounds of C n H 2n+1 radicles with a solution of ammonia in alcohol : Iodide of radicle. NH 3 = H -yl-ammonium iodide. The resulting compound is formed on the type of the salts of ammonia, and like these bodies is decomposed by fixed alkalies : N(C B H 2B+1 )H 8 T R -yl-ammonium iodide. KHO == N(C n H 2n+1 )H 2 Amine. OH + KI . At the same time, according to the proportion of the re agents, the temperature, &c., in the first reaction, more or less of the secondary and tertiary monamines are produced : 2CH 2)1+1 I 3C n H 2n+1 2NH 3 = N(C n H 2n+1 ) 2 H 2 I Secondary monamine hydriodlde. 3NH 3 = N(C B H 2B+1 ) 3 HI Tertiary monamine hydriodide. N(CH 3 )(C 2 H 5 )H 2 I Methyl-eth^ylammoniuni NH 4 I 2NH 4 I. Amines containing different radicles are obtained thus : N(C 2 H 5 )H 2 + CH 3 I = Ethylamine. Methyl iodide. The secondary and tertiary amines are in all these cases liberated by the action of KHO . 2. Cyanic and cyanuric acids (p. 554) form two classes of ethereal salts analogous to the cyanides and isocyanides (p. 555) ; thus N=C OR 0=C=N R Cyanatc. Isocyanate. Isocyanates are prepared by distilling ethereo-potassium salts of H 2 SO 4 containing the necessary radicles with po tassium cyanate: R KS0 4 + CO".NK = GO".NR + K 2 SO 4 . Isocyanurates are obtained by a similar reaction, substitut ing potassium cyanurate for cyanate. Both these classes of ethereal salts furnish primary amines on distillation with caustic alkali : CO.NR + 2KHO = NR H 2 + K 2 C0 3 , 3. Nitro-substitution derivatives of the paraffins are reduced by nascent hydrogen, ammonium sulphide, <tc., with the formation of amines (see reduction of nitroethane to ethylamine, p. 572). With the exception of the methylamines (which are gaseous), the amines of the present class are limpid liquids, having powerful ammoniacal odours and highly basic pro perties, restoring the colour of red litmus, and uniting with acids to form salts analogous to those of ammonium : N(CH 3 )H 2 + HC1 = N(CH 3 )H 3 C1 Methylamine. N(C 2 H 5 ) 3 Triethylamine. + HI = Methylammonium chloride. N(C,H 5 )JII Triethylumraoniuin

iodide.