Six-coordinate monooxo molybdenum(VI) complexes with N-4-diethylaminosalicylidene-N′-4-nitrobenzoyl hydrazine and catechol ligands: preparation and spectroscopic properties

Abstract Preparation and spectroscopic characterization are reported for monooxo molybdenum(VI) complexes, MoO(cat)L, where L 2−  = dianion of N -4-diethylaminosalicylidene- N ′-4-nitrobenzoyl hydrazine and cat 2−  = catecholate (Cat 2− ), 4-methylcatecholate (Mecat 2− ), 3,5-di- tert -butylcatecholate (DTBcat 2− ), or 4-nitrocatecholate (NO 2 cat 2− ). The compounds were prepared by replacement of an oxo group on MoO 2 L with a catechol. The MoO(cat)L complexes exhibit a Mo O stretching vibration ( ν Mo O ) at 935–938 cm −1 and a series of five absorptions in the UV–Vis region including a long wave-length band at 655–658 nm which is attributed to cat → Mo charge transfer. The 1 H and 13 C NMR data are reported and found to be consistent with the formation of monomeric MoO(cat)L compounds.