Synthesis, structure, luminescence properties, quantum chemistry and cytotoxic effects of two vanadium(IV) complexes with polypyrazolylborates, HB(pz)(3)VO(acac) and HB(3,5-Me(2)pz)(3)VO(acac)center dot CH3CN (pz = PYRAZOLE)

摘要

The reaction of VO(acac)(2) (acac = acetylacetonate) with NaHB(pz)(3) (pz = pyrazole) or NaHB(3,5-Me(2)pz)(3) in methanol gave vanadium(IV) complexes HB(pz)(3)VO(acac) (1) or HB(3,5-Me(2)pz)(3)VO(acac)(CH3CN)-C-. (2), respectively. The complexes 1 and 2 were characterized by elemental analysis, IR, UV-vis, NMR and X-ray diffraction crystallography methods. Complex 1 crystallizes in space group P2(1)/c, a = 7.641(2) angstrom, b = 17.008(4) angstrom, c = 13.362(2) angstrom; beta = 92.092(17)degrees, V = 1735.5(7) angstrom(3), Z = 4. Complex 2 crystallizes in space group P2(1)/c, a = 17.410(13) angstrom, b = 8.076(16) angstrom, c = 19.300(13) angstrom; beta = 101.75(5)degrees, V = 2657(6) angstrom(3), Z = 4. X-ray structure analyses have shown that the complexes 1 and 2 are monomeric with a similar coordination environment of the vanadium atom. Luminescence properties and cytotoxic effects of the complexes are discussed. On CBRH-7919 cells, the complexes 1 and 2 caused a slight stimulation of growth at low doses (1-10 mu M) and a significant cytotoxic effect at higher doses (100-1000 mu M). The electronic structure and the bonding characters of the two complexes were analyzed with ab initio calculations.