Model Studies of the Interaction of Vanadium(III) and Oxovanadium(IV/V) with the Carbonyl Amide Oxygen

A series of vanadium(III) and oxovanadium(IV/V) compounds with the ligands, N-(2-nitrophenyl)pyridine-2-carboxamide (Hpycan), N-(phenyl)pyridine-2-carboxamide (Hpheca), and N-(2-pyridyl)acetamide (Hpyra), containing the amide functionality, was prepared and characterized both in solution and in solid state. All vanadium compounds contain a vanadium−amide oxygen bond. Crystal data for [VOCl2(OC2H5)(Hpheca)] (4) are monoclinic; P21/a; a = 12.668(5) Å, b = 8.084(3) Å, c = 17.222(6) Å, α = 108.148(12)°; Z = 4. In addition to the synthesis and crystallographic studies, the optical, infrared, and magnetic properties of these compounds are reported. Electron paramagnetic resonance [of oxovanadium(IV) species] and 1H, 13C{1H}, and 51V nuclear magnetic resonance [of oxovanadium(V) compounds] properties are reported as well.