Biomimetic oxovanadium(IV) and (V) complexes with a tridentate (N,N,O)-donor hydrazonic ligand. Two X-ray crystal structure modifications of (2-acetylpyridine-benzoylhydrazonato)dioxovanadium(V)

• Published in: Transition metal chemistry (Weinheim) Vol. 30; no. 4; pp. 404 - 410
• Main Authors: Maia, Pedro Ivo da S., Deflon, Victor M., Souza, Elizeu J. de, Garcia, Edgardo, Sousa, Gerimário F. de, Batista, Alzir A., Figueiredo, Alberthmeiry T. de, Niquet, Elke
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01-05-2005
• Subjects: Crystal structure; Molecular structure
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-004-6972-5

Two oxovanadium(IV) and (V) complexes with 2-acetylpyridine-benzoylhydrazone have been prepared and characterized. The analytical methods used included elemental analysis, i.r., FAB^sup +^ m.s., ^sup 51^V-n.m.r. and e.p.r. X-ray diffractometry from single crystals as well as from microcrystalline material were also performed. Molecular modeling was used to calculate the complex structures in a vacuum and their vibrational frequencies. Octahedral coordination is suggested for the complex acetylacetonato(2-acetylpyridine-benzoylhydrazonato)-oxovanadium(IV) (1), for which good agreement was verified between calculated and observed i.r. data. Two crystal structure modifications of (2-acetylpyridine-benzoylhydrazonato)dioxovanadium(V) (2) have been determined by X-ray diffraction methods. In both crystalline modifications the molecular structure of the complex shows a distorted trigonal bipyramidal VN^sub 2^O^sub 3^ coordination. The molecular structure, found experimentally for (2), was compared with the theoretically calculated one. The results validate the theoretical method.[PUBLICATION ABSTRACT]