triphenylmethanol

As a derivative of methanol, triphenylmethanol is expected to have a pK in the range of 16-19.

Triphenylmethanol contains three phenyl rings and a hydroxyl group bound to a central tetrahedral carbon atom.

The preparation of triphenylmethanol from methyl benzoate or benzophenone and bromobenzene is a common laboratory experiment for teaching the Grignard reaction.

Triphenylmethyl hexafluorophosphate combined with water in basic conditions undergo hydrolysis to form triphenylmethanol and the conjugate acid hexafluorophosphoric acid.

In 1902, Norris and Kehrman independently discovered that colorless triphenylmethanol gave deep yellow solutions in concentrated sulfuric acid.

In alkaline solutions, nucleophilic hydroxyl ions attack the electrophilic central carbon to produce the colourless triphenylmethanol or carbinol form of the dye.

On the other hand, the basicity of triphenylmethanol is enhanced due to the formation of a stable carbocation upon breaking of the C-O bond.

In a highly acid solution, the protonated form of triphenylmethanol will lose the equivalent of a water molecule to form the highly stable triphenylmethylium carbocation.

Some triphenylmethanol is also formed under very acid condition when the positive charges on the nitrogen atoms lead to an enhancement of the electrophilic character of the central carbon which allows the nucleophilic attack by water molecules.

It may be prepared by the reaction of triphenylmethanol with acetyl chloride, or by the Friedel-Crafts alkylation of benzene with carbon tetrachloride to give the trityl chloride-aluminium chloride adduct, which is then hydrolyzed.