Synthesis and structural features of UVI and VIV chelate complexes with (hhmmbH)Cl·H2O [hhmmb = {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide], a new Schiff base ligand derived from vitamin B6

The Schiff base ligand {3-hydroxyl-5-(hydroxymethyl)-2-methylpyridine-4-yl-methylene}benzohydrazide hydrochloride monohydrated {(hhmmbH)Cl·H2O} (1) was prepared by reaction of pyridoxine hydrochloride with benzoic acid hydrazide. The reaction of 1 with [VO(acac)2] and triethylamine yields the neutral vanadiumIV complex [VO2(hhmmb)]·Py (2), with a distorted quadratic pyramidal configuration. The Schiff base 1 reacts also with UO2(NO3)2·6H2O and triethylamine under deprotonation giving the uraniumVI cationic complexes [UO2(hhmmb)(H2O)Cl]+ (3) and [UO2(hhmmb)(CH3OH)Cl]+ (4), both showing the classical pentagonal bipyrimidal geometry of UO22+ complexes. The structural features of all compounds are discussed.