Vanadium. Part X, Quinoline-, lsoquinoline-and Pyrazine Carboxylic Acid Complexes of Oxovanadium (IV)

Quinoline-3-carboxylic acid (8-QH) reacts with vanadium (IV) to produce light yellow [VO(H2O) (8-Q)2] H2O and six coordinated [VO (X) (8-Q)2] (where X= Pyridine aniline, \(\propto\)-pjcoline etc). Both the series give usual one unpaired electron magnetic moment. Isoquinoline carboxylic acid funrishes the light cream coloured mother compound but apparently no amine or base adduct. Pyrazine-2,3 dicarboxylic acid (PyrH2) produces [VO (Pyr)] (H2O)4 and with Pyridine [VO (Py) (Pyr)], in which l.he ligand behaves as a bidentate with the complexes being polymeric. These are also all paramagnetic. The electronic spectra reveals three distinct bands which is in keeping with the spectral characteristics obseved in similar other systems