Racemic monoperoxovanadium(V) complexes with achiral OO and ON donor set heteroligands: synthesis, crystal structure and stereochemistry of [NH3(CH2)(2)NH3][VO(O-2)(ox)(pic)].2H(2)O and [NH3(CH2)(2)NH3][VO(O-2)(ox)(pca)]
| Authors | |
|---|---|
| Year of publication | 2005 |
| Type | Article in Periodical |
| Magazine / Source | Dalton transactions : an international journal of organic chemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Inorganic chemistry |
| Keywords | PEROXOVANADIUM COMPLEXES; ANION-PI INTERACTIONS; MOLECULAR-STRUCTURE; HETEROLIGANDS |
| Description | Monoperoxovanadium(V) complexes, [NH3(CH2)(2)NH3][VO(O-2)(ox)(pic)]center dot 2H(2)O (1) and [NH3(CH2)(2)NH3][VO(O-2)(ox)(pca)] (2) [NH3(CH2)(2)NH3 = ethane-1,2-diammonium(2+), ox = oxalate(2-), pic = pyridine-2-carboxylate(1-), pca = pyrazine-2-carboxylate(1-)], were synthesized and characterized by X-ray analysis, IR and Raman spectroscopies. The five equatorial positions of the pentagonal bipyramid around the vanadium atoms are occupied by the eta(2)-peroxo ligand, two oxygen atoms of the ox, and the nitrogen atom of the pic or pca ligands, respectively. The oxo ligand and the oxygen atom of pic or pca are in the axial positions. Networks of X-H...O (X= C, N or O) hydrogen bonds, and pi-pi interactions between aromatic rings in 1 and anion-pi interactions in 2, determine the molecular packings and build up the supramolecular architecture. Three stereochemical rules for occupation of the donor sites in two-heteroligand [VO(O-2)(L-1)(L-2)] complexes (L-1, L-2 are bidentate neutral or differently charged anionic heteroligands providing an OO, NN or ON donor set) are discussed. 1 and 2 crystallize as racemic compounds. The V-51 NMR spectra proved that the parent complex anions of 1 and 2 partially decompose on dissolution in water to the monoperoxo-ox, - pic or -pca complexes. |
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