Structural, electron paramagnetic resonance and electron spin echo envelope modulation studies of oxovanadium(iv)–amidate compounds containing monoanionic axial ligands: effect on the 51V-hyperfine coupling constants

Abstract

Reaction of the amidate ligand N-{2-[(2-pyridylmethylene)amino]phenyl}pyridine-2-carbo xamide (Hcapca) with [VOCl2(thf)2] and MeONa in 1∶1∶1 molar ratio in MeCN affords the compound trans-[VOCl(capca)] 1, while reaction of 1 with NEt4NCS, MeCO2NHEt3 and imidazole yields the complexes trans-[VO(NCS)(capca)] 2, trans-[VO(Me- CO2)(capca)] 3 and trans-[VO(im)(capca)]− 4 respectively; the X-ray crystal structure of 1 is reported; Cw EPR studies of compounds 1–3 reveal a novel phenomenon of the reduction of their Az components by ca. 10% compared to N4 reference compounds.