Aerial oxidation of acetonitrile solutions containing VCl3 and pyrazole (pz), 3,5-dimethylpyrazole (3,5-Me(2)pz), or 3(5)-tert-butylpyrazole (t-Bupz) in a 1:3 mole ratio, or potassium hydridotris(3(5)-tert-butylpyrazolyl)borate (K[HB(t-Bupz)(3)]) in a 1:1 mole ratio, leads to the formation of a series of six-coordinate oxovanadium compounds. In the case of K[HB(t-Bupz)(3)] a facile B-N bond cleavage is observed. The compounds isolated include [(pz)(4)VOCl]Cl.H2O, I, (3,5-Me(2)pz)(2)VOCl2(H2O), II, (t-Bupz)(2)VOCl2, III, [(t-Bupz)(4)VO(H2O)]Cl-2.4CH(3)CN, IV, (t-Bupz)(2)VOCl2(F)VOCl(t-Bupz)(3), V, and (t-Bupz)(2)VO2F, VI. Compounds V and VI re suit from the treatment of LI[I or TV with AgBF4 or AgPF6. All compounds have been characterized by spectroscopic methods, magnetic susceptibility measurements, and X-ray crystallography. Crystal data : I, triclinic, P ($) over bar 1, a = 8.629(2) Angstrom, b = 8.666(1) Angstrom, c = 15.064(2) Angstrom, alpha = 106.13(1)degrees, beta = 101.61(1)degrees, gamma = 90.52(1)degrees, V = 1060.5(3) Angstrom(3), Z = 2, T = 298 K, R = 7.91%, R(W) = 9.88%; nr, monoclinic, C2/c, a = 12.402(2) Angstrom, b = 12.574(1) Angstrom, c = 9.854(1) Angstrom, beta = 97.66(1)degrees, V = 1522.9(2) Angstrom(3), Z = 4, T = 298 K, R = 3.22%, R(W) = 5.15%; III, tetragonal, P4(2)/n, a = 15.723(1) Angstrom, c = 15.677(1) Angstrom, V = 3875.6(5) Angstrom(3) Z = 8, T = 298 K, R = 5.23%, R(W) = 5.98%; IV, monoclinic, C2, a = 23.050(5) Angstrom, b = 7.452(2) Angstrom, c = 14.150(3) Angstrom, beta = 106.67(3)degrees, V = 2328.4(9) Angstrom(3), Z = 2, T = 298 K, R = 5.74%, R(W), = 7.76%; V, monoclinic, P2(1)/c, a = 12.997(4) Angstrom, b = 15.191(4) Angstrom, c = 23.497(7) Angstrom, beta = 97.25(2)degrees, V = 4602(1) Angstrom(3), Z = 4, T = 223 K, R = 3.80%, R(W) = 3.60%; VI, tetragonal, I4(1)cd, a = 32.698(3) Angstrom, V = 7470.8(11) Angstrom(3), Z = 16, T = 298 K, R = 6.40%, R(W) = 7.35%. Steric effects and hydrogen bonding are important factors in determining the solid state structures of compounds in this family. In particular, compound III exists as a helical solid state polymer stabilized by intrachain hydrogen bonding.