REACTIONS OF OXOVANADIUM(IV) AND OXOVANADIUM(V) DIPICOLINATO COMPLEXES WITH BENZOYLHYDRAZINE - CRYSTAL-STRUCTURES OF [VO(DIPIC)(NH2NHC(O)PH)].NH2NHC(O)PH.H2O, [C(NH2)3][VO(DIPIC)(NHNC(O)PH)].2H2O AND THE BLUE MODIFICATION OF [VO(DIPIC)(H2O)2].2H2O

The hydrazino complex [VO(dipic)(NH2NNC(O)Ph)].NH2NHC(O)Ph.H2O (3) has been prepared by reaction of [VO(dipic)(H2O)2].2H2O (1) with NH2NHC(O)Ph. (dipic = dianion of pyridine dicarboxylic acid). The hydrazido(2-) complex (guanid)[VO(dipic)(NHNC(O)Ph)].2H2O (4) was obtained by reaction of (guanid)[VO2(dipic)].2H2O and NH2NHC(O)Ph. During the course of this reaction a terminally bonded oxygen atom is abstracted from the vanadium(V) center. 1, 3 and 4 have been characterized by X-ray single crystal diffraction, infrared, Raman and electron spin resonance spectroscopy. In 1 vanadium is six-coordinate, with the nitrogen atom of the dipic ligand in trans position to the oxo group. The two water molecules are also ligated in mutual trans positions. Vanadium is also six-coordinate in 3 and 4. In both, the dipic ligand is cis oriented with respect to the terminal oxo group. In 3 benzoylhydrazine, and in 4 the hydrazido(2-) species NHNC(O)Ph act as N,O-chelate ligands, donating their NH2-, respectively NH-group to the remaining equatorial site and their CO-group to an axial site. The V-NH2 (213.1(4) pm) and V-NH (190.5(2) pm) bond lengths differ considerably, indicating multiple bond character for the latter. In 3 the V-O(oxo) and V-O(carbonyl) bond lengths are 160.1(4) and 219.1(3) pm, and in 4 160.8(2) and 211.9(2) pm, respectively. Crystal data for 1: space group P1BAR, a = 656.2(2), b = 913.2(3), c = 1075.2(2) pm, alpha = 111.44(2), beta = 100.16(2), gamma = 94.81(3)degrees, Z = 2; 3: space group P1BAR, a = 801.4(2), b = 1188.7(11), c = 1353.5(12) pm, alpha = 72.02(7), beta = 88.31(7), gamma = 70.60(7)degrees, Z = 2; 4: space group P1BAR, a = 1018.2(5), b = 1222.5(6), c = 1683.2(6) pm, alpha = 80.02, beta = 89.95, gamma = 78.73-degrees, Z = 4.