Hydrogen bonded dimer N-(2-hydroxyethyl)-2-oxy-1-naphthaldimine and its oxo-vanadium(V) complex

N-(2-hydroxyethyl)-2-oxy-1-naphthaldimin is a potential tridentate ligand p repared in a condensation reaction from 2-hydroxy-1-naphthaldehyde and 2-am inoethanol using catalytic amounts of triethylamine. Its vanadium(V) coordi nation compound was obtained by a template reaction from the methanol solut ion upon oxidation of VO2+ --> VO3+ in air. Physico-chemical properties of both compounds were examined by thermogravimetric analysis, differential sc anning calorimetry and FT IR spectroscopy. These results supplied some elem ents of structural information. Nevertheless, the entire stereochemistry of both the non-coordinated ligand and metal complex was elucidated by the X- ray structural determination. The ligand forms molecular complex by dimeriz ation via intermolecular O-H ... O hydrogen bonding. In the metal complex, four square pyramid basal plane coordination places are occupied by dinegat ive tridentate ligand ONO donor atoms and a methoxy group. All V-O bond dis tances are significantly different, depending on the nature of the function al group to which oxygen atoms belong. The vanadium complex is an example o f a fairly rare pentacoordinated square pyramidal V-V species.