They behave in most respects as unsaturated compounds; they combine with hydrogen to form amines; with water to form acidamides; with sulphuretted hydrogen to form thio-amides; with alcohols, in the presence of acids, to form imido-ethers R C(:NH) OR'; with ammonia and primary amines to form amidines R C(:NH) NH 2 i and with hydroxylamine to form amidoximes, R C(:NOH) NH 2.
Attempts to eliminate water from this acid and so produce an unsaturated acid were unsuccessful; on warming with sulphuric acid, carbon monoxide is eliminated and cyclo-butanone (keto-tetramethylene) is probably formed.
The chief unsaturated hydrocarbons present in coal gas are: ethylene, C2H4, butylene, C 4 H 8, acetylene, C 2 H 2, benzene, C 6 H 61 and naphthalene,C 10 H 8, and the saturated hydrocarbons consist chieflyof methane, CH 4, and ethane, C2H6.
From the fact that reduction products containing either one or two double linkages behave exactly as unsaturated aliphatic compounds, being readily reduced or oxidized, and combining with the halogen elements and haloid acids, it seems probable that in benzenoid compounds the fourth valencies are symmetrically distributed in such a manner as to induce a peculiar stability in the molecule.
Cyclo-octane, C 8 H, 6 is obtained by the reduction of the above unsaturated hydrocarbon by the Sabatier and Senderens's method.
Blanc, Comptes rendus, 1903, 136, p. 1676; 137, p. 60); and by the addition of the elements of water to the unsaturated cyclic hydrocarbons on boiling with dilute acids.
The unsaturated members of the series are named on the Geneva system in which the termination -ane is replaced by-ene, -diene, -triene, according to the number of double linkages in the compound, the position of such double linkages being shown by a numeral immediately following the suffix -ene; for example I.
The unsaturated fatty acids which occur chiefly in oils and fats are oleic acid, iodine value 90.07; erucic acid, iodine value 75.15; linolic acid, iodine value 181.42; linolenic acid, iodine value 274.1; and clupanodonic acid, iodine value 367.7.
Acid esters yield carbinols, many of which are unstable and readily pass over into unsaturated compounds, especially when warmed with acetic anhydride: R.
His most important contribution to organic chemistry was a series of researches, begun in 1835, on the haloid and other derivatives of unsaturated hydrocarbons.