Kinetic studies on the solvolysis and axial ligand substitutions of bis-triphenylphosphine(cyclohexane-1,2-dione-dioximato)ruthenium(II) in non-aqueous solvents |
| |
| Authors: | Bakhsh M Majid R El-Awady Abbas A Khalifa Mohamed A |
| |
| Institution: | (1) Department of Chemistry, King Abdulaziz University, P.O. Box 9028, Jeddah, 21413, Saudi Arabia;(2) Department of Chemistry, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria, 2132, Egypt |
| |
| Abstract: | Kinetic studies of ligand substitutions of the six-coordinated RuII pseudo-macrocyclic complex Ru(CHDH)2- (PPh3)2] (CHDH =cyclohexanedione-dioximato) have been spectrophotometrically investigated in a variety of solvents and at 70, 80, 85 and 90°C. The reactions studied are of the form:(PPh3)Ru(CHDH)2(PPh3)] + L =(PPh3)Ru(CHDH)2L] + PPH3
where L is imidazole, pyridine, piperidine or thiophene or a solvent molecule (PhCl, PhMe, MeCN, DMSO or DMF). The solvolysis reactions with chlorobenzene and toluene proceed to an equilibrium position favoring the bis-triphenylphosphine complex. All other reactions proceed to completion. From a mechanistic point of view the reactions were found to proceed through the formation of a five coordinate intermediate that possesses little or no discriminating ability towards the incoming nucleophiles. The rate data were thus interpreted in terms of a dissociative (D) or dissociative interchange (Id) mechanism. Activation parameters  H and S are reported. Preliminary studies on the solvatochromic behavior of Ru(CHDH)2(PPh3)2] and the corresponding mixed complexes are discussed. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
