Complexes of tungsten(IV,VI) and molybdenum(V) derived from 1,2-diaminobenzene. X-ray crystal structures of cis,mer-W(o-NC6H4NH2)Cl2(PMe3)3, {WCl[o-(HN)2C6H4]2(PMe32}(BPh4 and mer,transMo(o-NC6H4NH2)Cl3(PMePh2)2

The compound WCl2(PMe3)4 undergoes an oxidative-addition reaction with excess o-phenylenediamine (1,2-diaminobenzene) in refluxing toluene to give the tungsten(IV) imido complex cis,mer-W(o-NC6H4NH2)Cl2(PMe3)3 (1). A chloride substitution reaction of 1 with NaBPh4 leads to the seven-coordinate tungsten(VI) complex {WCl[o-(HN)2C6H4]2(PMe3)2}(BPh4) (2). Interaction of MoOCl2(PMePh2)3 with excess o-phenylenediamine in the presence of base (Et3N) gives the imido complex mer,trans-Mo(o-NC6H4NH2)Cl3(PMePh2)2 (3). X-ray structures of the compounds listed in the title have been determined. In 1 and 3 the pseudo-octahedral complexes contain unidentate nearlinear imido groups, derived from the o-phenylenediamine ligand, whereas in complex 2 the geometry is distorted capped octahedral with chelating (HN)2C6H4 groups.