Oxovanadium(IV) pyrazolyl carboxylic acid complexes: synthesis, crystal structures of [VO(pzH)(HMPA)₂]₂ · 4H₂O (1) and VO(OH)(dmpzH)₂(C₆H₅COO) (2) (H₂MPA = 5-methyl-1H-pyrazole-3-carboxylic acid, pzH = pyrazole, dmpzH = 3,5-dimethyl pyrazole)

摘要

Two new monomeric complexes of oxovanadium(IV), [VO(pzH)(HMPA)₂]₂ · 4H₂O (1) and VO(OH)(dmpzH)₂(C₆H₅COO) (2) (H₂MPA = 5-methyl-1H-pyrazole-3-carboxylic acid, pzH = pyrazole, dmpzH = 3,5-dimethyl pyrazole), have been synthesized from reaction of VOSO₄ · nH₂O with respective ligands. The compounds were characterized by elemental analysis, IR spectra and X-ray diffraction. Structural analysis of 1 and 2 gave the following parameters: 1, monoclinic, P2(1), a = 11.1729(13) à , b = 23.965(3) à , c = 13.5591(15) à , β = 99.969(2)°, V = 3575.8(7) à 3, Z = 4; 2, orthorhombic, Pbcn, a = 13.197(4) à , b = 15.898(5) à , c = 18.192(6) à , V = 3817(2) à 3, Z = 8. In each complex the vanadium is a distorted tetragonal bipyramid, which is typical for oxovanadium(IV) complexes. In both complexes, inter- and intra-molecular hydrogen bonds are also discussed. Complex 1 exists as an infinite chain along the b-axis by intermolecular hydrogen bonds. In addition, thermal analysis and quantum chemistry calculations were performed for analyzing the stability of the complexes.View full textDownload full textKeywordsOxovanadium(IV) complexes, Pyrazole ligand, Carboxylic acid, Hydrogen bonds, Crystal structuresRelated var addthis_config = { ui_cobrand: "Taylor & Francis Online", services_compact: "citeulike,netvibes,twitter,technorati,delicious,linkedin,facebook,stumbleupon,digg,google,more", pubid: "ra-4dff56cd6bb1830b" }; Add to shortlist Link Permalink http://dx.doi.org/10.1080/00958970802298402