Vanadium(II) chemistry. Part I. Magnetic and spectroscopic investigations of the sulphate and double sulphates

Abstract
The simple sulphate VSO4,6H2O has been prepared by electrolytic reduction, and the Tutton salts M2[V(H2O)6](SO4)2(M = NH4, K, Rb, and Cs) have been obtained from it by the addition of the appropriate univalent sulphate. The sulphate is commonly reported as a heptahydrate, but in this investigation only a hexahydrate, which is probably isomorphous with ZnSO4,6H2O, has been obtained. The magnetic moments are a little below the spin-only value (3·87 B.M.) and are invariant with temperature. Electronic reflectance spectra at room temperature and liquid-nitrogen temperatures are consistent with vanadium(II) in Oh symmetry, with values of 10Dq,B, and C of approximately 12,000, 650, and 2600 cm.–1 respectively.