Gomberg's triphenyl-methyl play no part in what follows), it is readily seen that the simplest hydrocarbon has the formula CH 4, named methane, in which the hydrogen atoms are of equal value, and which may be pictured as placed at the vertices of a tetrahedron, the carbon atom occupying the centre.
Two acids corresponding to the formula of Kekule and Claus are triphenyl acrylic acid, (C6H5)2C: C([[Cooh) C 6 H]],, and triphenyl acetic acid, (C,H,),C 000H.
Von Liebig (Ann., 1908, 360, p. 128), from a very complete discussion of triphenyl methane derivatives, concluded that the group i ng A A A was the only true organic chromophore, colour production, however, requiring another condition, usually the closing of a ring.
Busch (Ber., 1905, 38, pp. 856, 4049) has isolated a series of bridged ring compounds which he describes as endo-iminodihydrotriazoles, the triphenyl derivative (annexed formula) being prepared by condensing triphenylaminoguanidine with formic acid.