Molecular, supramolecular and solution structures of peroxovanadium complexes with ON and O3N donor set ligands: two new types of cationic-anionic peroxovanadium(V) peroxovanadates(V)

Warning

This publication doesn't include Faculty of Sports Studies. It includes Faculty of Science. Official publication website can be found on muni.cz.

Authors	MAĎAROVÁ M. SIVÁK M. KUCHTA L. MAREK Jaromír BENKO J.
Year of publication	2004
Type	Article in Periodical
Magazine / Source	Dalton transactions : an international journal of organic chemistry
MU Faculty or unit	Faculty of Science
Citation
Field	Inorganic chemistry
Keywords	vanadium (V); peroxo complexes; X-ray structure; hydrogen bonds; NMR spectroscopy
Description	The complexes, [VO(O-2)(pa)(2)] ClO4 . 3H(2)O ( 1), [VO(O-2)(pa)(2)][ VO(O-2)(2)(pa)] . 3H(2)O (2), [VO(O-2)(pa)(2)][VO(O-2)( ada)] . 2H(2)O ( 3) and [VO(O-2)(pa)(pca)] . H2O ( 4) [pa = picolinamide, ada = carbamoylmethyliminodiacetate( 2-) and pca = 2- pyrazinecarboxylate(1-)], were synthesized. 2 and 3 are new types of peroxovanadium complexes: monoperoxovanadium diperoxovanadate ( 2) and monoperoxovanadium monoperoxovanadate ( 3). The complexes were characterized by chemical analysis and IR spectroscopy, and 1, 3 and 4 also by X-ray analysis. The structure of 1 is disordered, with alternating positions of the oxo and peroxo ligands. The peroxo oxygen atoms, O-p, in 1 are involved in weak hydrogen bonds with water molecules and close intramolecular C - H...O-p bonds [d(H...O-p) similar to 2.0 Angstrom]. The supramolecular structure of 1 is formed by a network of hydrogen bonds and strong attractive intermolecular pi - pi interactions between the pyridine rings. The supramolecular architecture in 4 is constructed by (N, O) - H...O hydrogen bonds between the neutral complex molecules and water of crystallization. The peroxo oxygen atoms in 4 form intramolecular C - H...O-p bonds [d( H...O-p) = 2.303 Angstrom]. The pa and pca ligands are ON coordinated via the oxygen atoms of the C(NH2)=O and COO- groups, respectively, and nitrogen atoms of the heterocyclic rings, and ada as a tetradentate O3N ligand. The thermal analysis of 4 showed that the loss of water of crystallization and the active oxygen release (T-min/degreesC 82, T-max/degreesC 165) are, under given conditions, individual processes separated by the temperature interval 90 - 132 degreesC. The solution structures and stability were studied by UV-VIS and V-51 NMR spectroscopies.
Related projects:	Genomes and their functions