Preparation of vanadium(II) compounds. Structures of a carboxylato and a 3-pyridinesulphonate compound

Abstract

Reactions of aqueous vanadium(II) sulphate with pyridine-2-carboxylate (and other carboxylic acids) and 3-pyridinesulphonate (pySO 3) salts have been investigated, as well as the reaction of the products with pyridine. Two of the products have been structurally characterized by X-ray crystallography. An aquo carboxylato compound, [V(Pic) 2(H 2O) 2]·2H 2O ( I) (Pic = anion of picolinic acid), crystallizes in the monoclinic space group P2 1/ n with a = 9.930(2), b = 5.169(1), c = 14.543(2) Å, β = 90.35(2)°, V = 746.1(2) Å 3 and Z = 2. Extensive hydrogen bonding in the structure provides sufficient protection to the metal centre to make the crystals relatively stable in air. The pyridine adduct V(pySO 3) 2(py) 4 ( II) possesses a molecular structure and crystallizes in the monoclinic space group C2/ c with a = 17.033(4), b = 11.218(4), c = 17.396(4) Å, β = 110.05(2)°, V = 3122(2) Å 3 and Z = 4. Both compounds exemplify the facile formation of bonds between vanadium(II) and nitrogen-containing ligands.