THE SYNTHESIS, PROPERTIES AND STRUCTURES OF THE TETRAPHENYL-ARSONIUM SALTS OF [V2O3(NO3)(2)X-4](2-), X = CL OR NO3

The complexes [Ph4As](2)[V2O3(NO3)(6)], 1 and [Ph4As](2)[V2O3Cl4(NO3)( 2)], 2, crystallise from solution in the reaction of tetraphenylarsoni um nitrate with VO(NO3)(3) and VOCl3, respectively. The compounds were characterised by their IR and Raman spectra and single crystal X-ray analysis. Compound 1 crystallises in the triclinic space group P (1) o ver bar, a = 9.580(1), b = 10.782(2), c = 13.631(2) Angstrom, Z = 1 an d R = 0.059, whilst 2 crystallises in the monoclinic space group P2(1) /c, a = 10.1.76(1), b = 17.691(2), c = 13.955(2), Z = 2 and R = 0.034. The crystal structures show that the dianions are related, the vanadi um atoms in both species possess distorted octahedral symmetry, this b eing achieved by one terminal and one bridging oxygen atom, one bident ate nitrate group and four other monodentate ligands. An unusual featu re of 1 is the presence of both monodentate and bidentate modes of nit rate coordination whilst 2 is the first example of a mixed halonitrato species of vanadium(V) to be isolated. (C) 1998 Elsevier Science Ltd. All rights reserved.