Molybdenum(VI), (V) and (IV) complexes with chiral benzoin thiosemicarbazone

The chiral (ONS) dianionic Schiff base ligand benzoin thiosemicarbazone (H2L) reacts with MoO2(acac)2 to give the polymeric complex [(MoO2L)n] (1) (Type 1). The reaction of MoO2L with pyridine (py), 3-picoline (3-pic) or 4-picoline (4-pic) gives [MoVIO2LD] (D = py, 3-pic or 4-pic) (Type 1). Further, the reaction of [MoO2L] or [MoO2LD] with PPh3 or reaction of [MoO2L] with PPh3 (plus bpy or phen, D) in the presence of donor reagents D gives [MoIVOL] or [MoIVOLD] (Type 2). On the other hand, the reaction of [MoO2L] with hydrazides (zdhH3) such as benzoylhydrazine (bhH3), isonicotinoylhydrazine (inhH3), nicotinoylhydrazine (nhH3), salicyloylhydrazine (slhH3) and thiosemicarbazide (tscH3) produced non-oxo–diazenido complexes [MoL(zdh)] (Type 3). The complexes have been characterized by elemental analyses, molar conductance, magnetic moment, electronic, i.r. and e.s.r. spectroscopic measurements.