Diazodiphenylmethane is an organic reagent with the chemical formula C<sub>13</sub>H<sub>10</sub>N<sub>2</sub>. It exists as red-black crystals that melt just above room temperature.
Diazodiphenylmethane can be synthesized via the oxidation of benzophenone hydrazone with mercury(II) oxide in diethyl ether and the presence of a basic catalyst. An improved procedure involves dehydrogenation with oxalyl chloride.
Like all diazo compounds, diazodiphenylmethane is an alkylating agent, forming diphenylmethyl esters and ethers with carboxylic acids and alcohols, respectively.
When heated or illuminated with ultraviolet light, the compound decomposes, forming (diphenyl)methyl carbene and nitrogen gas. Electrolytic reduction in dimethylformamide with tetrabutylammonium perchlorate cosolute generates the Ph<sub>2</sub>CN radical anion, which also loses N<sub>2</sub>. The resulting Ph<sub>2</sub>C<sup>âÂÂ</sup> radical anion can attack other molecules of diazodiphenylmethane to form benzophenone azine, which has the formula Ph<sub>2</sub>C=N-N=CPh<sub>2</sub>.