A treatise on chemistry. Vol. III, The chemistry of the hydrocarbons and their derivatives, or, Organic chemistry. Part I / by H.E. Roscoe & C. Schorlemmer.

Henry Enfield Roscoe

Date:: 1881

Credit: A treatise on chemistry. Vol. III, The chemistry of the hydrocarbons and their derivatives, or, Organic chemistry. Part I / by H.E. Roscoe & C. Schorlemmer. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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$12-1 ISOMERISM. o-Butvlone. /3-Butylcne. Isobutylene. CH3 CH3 CH3 CH3 I I \ ^ CH., CH G I I! II CH CH CH, II I CHg ^-^3 It has already been stated that the hydrocarbons of the series CnH2n have been assumed to contain free combining units. If this were the case, four propylenes and eight butylenes must exist. If, however, these hydrocarbons be supposed to contain two carbon atoms having a double linking, only one propylene and three butylenes can exist, and this has been proved to be the fact. In the case of the hydrocarbons of the series C„H2ii-2> a- still larger number of cases of isomerism are possible. Thus, for instance, we have two substances having the formula CgH^. Allylp.ne. Iso-allylene. CH3 CHg I II c c 111 II CH CH, A large group of carbon compounds are derived from benzene, CgHg. In these the carbon atoms are linked together in a peculiar way, the nature of which will be hereafter explained. The homologues of this series are formed by the replacement of one or more atoms of hydrogen by alcohol radicals, and hence a variety of isomerides is formed, such as the following: (1) (2) Ethyl-benzene. Dimetliyl-benzene. CoHj-CaHg CyH^ I (1) (2) (3) (4) Propyl- Lsopropyl- IMethyl-ethyl- Ti-iniethyl- beiizene. bpiizeuc. benzene. bL-nzeno. C„H,.C3H, C„H,.CH(CH3)2 C„H, ^ '^^ C,H3] CH, ^ - •' ICH3 The foregoing cases do not, however, exhau -t the number of cNisting isomeric bodies, inasmuch as two or more atoms of$