Nucleophilic Reactions of Hydrazido(2–) Complexes of Molybdenum and Tungsten with Succinyl Dichloride and Phenyl Isocyanate

Nucleophilic attack of the WNNH2 group in the hydrazido(2-) complex [WF(NNH2)(dpe)2][BF4] (dpe=Ph2PCH2CH2PPh2) on succinyl dichloride gives a novel ethanedioylhydrazido(2-) complex, [WF(NNCOCH2CH2CO)(dpe)2][BF4]. X-Ray structural analysis shows that the carbon, nitrogen, and oxygen atoms of the ethanedioylhydrazido(2-) ligand lie nearly in the same plane, indicating sp2 character of the nitrogen atom bearing the two carbonyl groups. Phenyl isocyanate also undergoes nucleophilic attack by the hydrazido(2-) complex [MBr(NNH2)(dpe)2]Br (M=Mo or W) to yield the phenylsemicarbazido(2-) type complex, [MBr(NNHCONHPh)(dpe)2Br. Treatment of the semicarbazido(2-) complex with triethylamine gives a new diazenido complex [MBr(NNCONHPh)(dpe)2].