Preparation of dinitrogen complexes Mo(N2)2P4 stabilised by phosphonite PPh(OEt)2 and phosphinite PPh2(OEt) ligands

Dinitrogen complexes Mo(N2)2P41, 2 [P=PPh(OEt)2 and PPh2OEt] were prepared by allowing a MoCl3(THF)3 solution containing an excess of phosphine to react with magnesium under nitrogen. Substitution reactions with CO and p-tolylisocyanide were studied, and led to Mo(CO)2P4, Mo(CO)3P3, and Mo(p-tolylNC)2P4 derivatives. Treatment of dinitrogen compound Mo(N2)2[PPh(OEt)2]4 with an excess of HCl gave the hydrazido(2-) [MoCl(NNH2){PPh(OEt)2}4]Cl derivative. Reduction reactions with zinc amalgam of complexes 1 and 2 in the presence of lutidine·HCl gave ammonia in about 8–10% yield.