 It is a colorless crystalline material that is widely used as a building block in organic synthesis and as a ligand in organometallic chemistry.In one preparation for this compound, benzil is condensed with hydrazine to give the bis(hydrazone), which is oxidized with mercury oxide.Alternatively stilbene is brominated, and the resulting dibromodiphenylethane is subjected to dehydrohalogenation, Yet another method starts involves the coupling iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling.