New Scorpionate Oxovanadium Complexes: Syntheses and Crystal Structures of a Series of Vanadium (IV) Complexes with Mixed Ligands of Polypyrazolylborates and Substituted Acetylacetonates
Free accessResearch articleFirst published online February, 2007
New Scorpionate Oxovanadium Complexes: Syntheses and Crystal Structures of a Series of Vanadium (IV) Complexes with Mixed Ligands of Polypyrazolylborates and Substituted Acetylacetonates
The reaction of [VO(R1-acac)2] (R1 = Me or Et; acac = acetylacetonate) with Na[HB(pz)3] (pz = pyrazole) or Na[HB(3,5-Me2pz)3] in MeOH gave a series of new oxovanadium (IV) complexes: [VO{HB(pz)3}(Me-acac)] (1), [VO{HB(3,5-Me2pz)3}(Me-acac)] (2), [VO{HB(pz)3}(Et-acac)] (3) and [VO{HB(3,5-Me2pz)3}(Et-acac)] (4), respectively. All complexes have similar distorted octahedral coordination about vanadium, [VO(N3O2)], in which the basal plane is defined by the N4, N6 atoms from the tridentate ligand and the O2, O3 atoms from the R1-acac ligand. However, the dihedral angles between the plane formed by O2, V and O3, and the plane of the pentane-2, 4-dionato ligand (O2, C1, C2, C3 and O3) are variously different; 3.59° for 1, 74.54° for 2, 0.92° for 3, and 29.50° for 4, respectively. In addition, ab initio calculations on 1, 2, 3 and 4 have given the energies and characters of the selected MOs, the atomic net charge and the NBO bond order. The order of stability of the complexes is 1 ≅ 2 ≅ 4 > 3.
(a) FujimotoS., FujiK., YasuiH., MatsushitaR., TakadaJ., and SakuraiH., J. Clin. Biochem. Nutr., 1997, 23, 113; (b) D.C. Crans, J.J. Smee, E. Gaidamauskas and L. Yang, Chem. Rev., 2004, 104, 849; (c) P. Noblía, M. Vieites, B.S. Parajón-Costa, E.J. Baran, H. Cerecetto, P. Draper, M. Gonzalez, O.E. Piro, E.E. Castellano, A. Azqueta, A. Lopez de Cerain, A. Monge-Vega and D. Gambino, J. Inorg. Biochem., 2005, 99, 443.
2.
(a) SakuraiH., TamuraA., TakinoT., OzutsumiK., and KawabeK., KojimaY., Inorganic Reaction Mechanisms., 2000, 2, 69; (b) X.-Y. Yu, S.-H. Cai and Z. Chen, J. Inorg. Biochem., 2005, 99, 1945; (c) M. Nakai, F. Sekiguchi, M. Obata, C. Ohtsuki, Y. Adachi, H. Sakurai, C. Orvig, D. Rehder and S.Yano, J. Inorg. Biochem., 2005, 99, 1275.
3.
(a) TakinoT., YasuiH., YoshitakeA., HamajimaY., MatsushitaR., TakadaJ., and SakuraiH., J. Bio. Inorg. Chem.6 (2001) 133; (b) O. Bortolini and V. Conte, J. Inorg. Biochem., 2005, 99, 1549.
4.
SakuraiH., TsuchiyaK., and KomatsuM., J. Clin. Biochem. Nutr., 1990, 8, 193.
5.
(a) McNeilJ.H., YuenV.G., HoveyaH.R., and OrvigC., J. Med. Chem., 1992, 35, 1489; (b) H. Ou, L. Yan, D. Mustafi, M.W. Makinen and M.J. Brady, J Biol Inorg. Chem., 2005, 10, 874.
6.
TawaR., UchidaK., TaniyamaJ., FujisawaY., FujimotoS., NagaokaT., KanamoriK., and SakuraiH., J. Pharm. Pharmacol., 1999, 51, 119.
