ROLE OF THE LIGAND IN THE FORMATION OF SHORT VANADIUM VANADIUM CONTACTS - PREPARATION AND CRYSTAL-STRUCTURE OF MONOMERIC ([(PH2P)2CH]3V)[LI(THF)4](THF)2 AND [PHNC(H)NPH]2V(TMEDA) AND DIMERIC ([PHNC(ME)O]2V)2(TMEDA) (TMEDA=N,N,N',N'-TETRAMETHYLETHYLENEDIAMINE)

A chloride substitution reaction in trans-VCl2(TMEDA)2 (TMEDA = N,N,N',N'-tetramethylethylenediamine) with anionic, bidentate, bridging [(Ph2P)2CH]- (I), [PhNC(H)NPh]- (II), and [PhNC(Me)O]- (III) allowed the preparation and characterization of four novel V(II) complexes: monomeric {[(Ph2P)2CH]3V}[Li(THF)4](THF)2 (1), [PhNC(H)NPh]2V(TMEDA) (3), and (DMOB)2V(TMEDA) (5) (DMOB = 2,6-dimethoxyphenyl) and dimeric {[PhNC(Me)O]2V}2(TMEDA) (4). The structures of 1, 3, 4, and 5 have been demonstrated by X-ray analysis. Crystal data are as follows. 1: C99H111P6O6VLi, M = 1640.69, monoclinic, P2(1)/n, a = 15.496 (2) angstrom, b = 26.264 (6) angstrom, c = 24.283 (7) angstrom, beta = 99.22 (2)degrees, V = 9755 (4) angstrom 3, Z = 4; 3: C32H38N6V.C4H8O, M = 629.75, monoclinic, P2(1)/c, a = 10.914 (4) angstrom, b = 21.301 (5) angstrom, c = 14.446 (3) angstrom, beta = 91.82 (3)degrees, V = 3356.7 (4) angstrom 3, Z = 4; 4: C38H48N6O4V2, M = 754.72, triclinic, P1, a = 10.293 (1) angstrom, b = 11.323 (1) angstrom, c = 17.550 (3) angstrom, alpha = 102.01 (2)degrees beta = 93.02 (2)degrees, gamma = 108.63 (2)degrees V = 1880.1 (5) angstrom 3, Z = 2.