Chemistry of ruthenium with some dioxime ligands. Syntheses, structures and reactivities

Citation
Ak. Das et al., Chemistry of ruthenium with some dioxime ligands. Syntheses, structures and reactivities, POLYHEDRON, 20(3-4), 2001, pp. 327-335
Citations number
63
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Inorganic & Nuclear Chemistry
Journal title
POLYHEDRON
ISSN journal
0277-5387 → ACNP
Volume
20
Issue
3-4
Year of publication
2001
Pages
327 - 335
Database
ISI
SICI code
0277-5387(20010215)20:3-4<327:CORWSD>2.0.ZU;2-P
Abstract
Reaction of two dioxime ligands, viz. dimethylglyoxime (H(2)dmg) and diphen ylglyoxime (H(2)dpg), (abbreviated in general as H2L, where H stands for th e oxime protons) with [Ru( PPh3)(3)Cl-2] in 1:1 mole ratio affords complexe s of type [Ru(PPh3)(2)(H2L)Cl-2]. Structure of the [Ru(PPh3)(2)(H(2)dpg)Cl- 2] complex has been solved by X-ray crystallography. The coordination spher e around ruthenium is N2P2Cl2 with the two PPh3 ligands in trans and the tw o chlorides in cis positions. Reaction of the dioxime ligands with [Ru(PPh3 )(3)Cl-2] in 2:1 mole ratio in the presence of a base affords complexes of type [Ru(PPh3)(2)(HL)(2)]. Structure of the [Ru(PPh3)(2)(Hdmg)(2)] complex has been solved by X-ray crystallography. The coordination sphere around ru thenium is N4P2 with the two PPh3 ligands in trans positions. Reaction of t he [Ru(PPh3)(2)(H(2)dpg)Cl-2] complex with a group of bidentate acidic liga nds, viz. picolinic acid (Hpic), quinolin-8-ol (Hq) and 1-nitroso-2-naphtho l (Hnn), (abbreviated in general as HL', where H stands for the acidic prot on) in the presence of a base affords complexes of type [Ru(PPh3)(2)(H(2)dp g)(L')](+) isolated as perchlorate salts. All the complexes are diamagnetic (low-spin d(6), S = 0) and in dichloromethane solution show several intens e MLCT transitions in the visible region. Cyclic voltammetry on all the com plexes shows a reversible ruthenium(II)-ruthenium(III) oxidation within 0.3 6-0.98 V versus SCE followed by a quasi-reversible ruthenium(III)-ruthenium (IV) oxidation within 0.94-1.60 V versus SCE. (C) 2001 Elsevier Science B.V . All rights reserved.