Di-, Tri- and Tetra-Phenylmethanes, their Derivatives and Oxidation Products

Publisher Summary This chapter describes the di-, tri-and tetra-phenylmethanes, their derivatives and oxidation products. It reviews the general methods of preparation and properties of diphenylmethane and its nuclear-substituted derivatives, diphenylmethyl halides or benzhydryl halides, benzhydrylidene dihalides, diphenylmethylamines or benzhydrylamines, and their nuclear-substituted derivatives, diphenylmethanol or benzhydrol and its nuclear-substituted derivatives, benzophenone and its nuclear-substituted derivatives. Substituted triphenylmethanes acquired prominence in the form of some of the earliest synthetic dyestuffs, such as fuchsin.Triphenylmethanol is the parent of many derivatives of considerable practical importance. Dyeings with triarylmethane dyes are brilliant in hue but generally not very stable when exposed to light except in a dry atmosphere or when applied to certain synthetic materials, for example, polyacrylonitrile fibers. Phthaleins are colorless, high-melting (generally with decomposition) crystalline substances, generally sparingly soluble in water or alcohol, but dissolving in alkalis to give highly colored solutions. The parent compound, tetraphenylmethane, Ph4C, for which the trivial name tetratane has been suggested (by analogy with tritane for triphenylmethane), was first obtained from the thermal decomposition of benzeneazotriphenylmethane. Subsequently, tetraphenylmethane and its derivatives have been isolated in low yields from several similar reactions, which are now known to involve triphenylmethyl radicals.