Considerable interest is attached to the remarkable series of hydrocarbons obtained by Gomberg (Ber., 1900, 33, p. 3150, et seq.) by acting on triphenylmethane chloride (from triphenylmethane carbinol and phosphorus pentachloride, or from carbon tetrachloride and benzene in the presence of aluminium chloride) and its homologues with zinc, silver or mercury.
Triphenylmethane chloride yields triphenylmethyl; ditolylphenylmethyl and tritolylmethyl have also been prepared.
It sometimes separates with crystals of a solute as " benzene of crystallization," as for example with triphenylmethane, thio-p-tolyl urea, tropine, &c.
Fischer showed that these compounds were derivatives of triphenylmethane and tolyldiphenylmethane respectively.
The reverse series of operations was also carried out by the Fischers, triphenylmethane being nitrated, and the nitro compound then reduced to triaminotriphenylmethane or paraleucaniline, which on careful oxidation is converted into the dyestuff.