eCite Digital Repository

Novel cationic and neutral Pd(II) complexes bearing imidazole based chelate ligands: synthesis, structural characterisation and catalytic behaviour

Citation

Denney, MC and Ruether, T and Cavell, KJ and Kilner, M and Peacock, EJ and Braussaud, N and Skelton, BW and White, A, Novel cationic and neutral Pd(II) complexes bearing imidazole based chelate ligands: synthesis, structural characterisation and catalytic behaviour, Journal of Organometallic Chemistry, 607, (1-2) pp. 78-92. ISSN 0022-328X (2000) [Refereed Article]

DOI: doi:10.1016/S0022-328X(00)00227-8

Abstract

A variety of neutral and cationic methyl palladium(II) complexes [Pd(CH3)(Cl)(L-L)] (3) and [Pd(CH3)(CH3CN)(L-L)]BF4 (4), containing known and new N-methylimidazole-2-yl (mim) and N-methylbenzimidazole-2-yl (bmim) based chelate ligands (L-L) have been synthesised. The dichloro complexes [Pd(Cl)2{(mim)2CO}] (2b) and [Pd(Cl)2(mim)PPh2] (2e) have also been synthesised. The crystal structures of [Pd(Cl)2{(mim)2C=NPh}] (2d) and [Pd(CH3)(Cl){(bmim)2CO}] (3c) have been determined and show a square planar geometry at palladium(II) with an appreciable diminished bite angle (85.6°) in 3c compared to 2d (88.5°). The molecular structure of 2d and 3c show both bisimidazole ligands coordinated via the ring nitrogen donors and inclination of the chelate ring bridge to the coordination plane (boat conformation). Low temperature NMR spectra indicate boat-to-boat inversion of the chelate ring in [Pd(CH3)(CH3CN){(mim)2CO}]+ (4b). Examples of the neutral and cationic complexes were tested in the Heck reaction and CO/ethylene copolimerisation respectively. The C=O bridged bisimidazole complex (3b) exhibited high activity (TON of 100 000) in the Heck reaction whereas the closely related benzimidazole complex 3c was about half as active (TON of 53 000). Low activities were found for the cationic complex 4b in the CO/ethylene copolymerisation (TON 449). © 2000 Elsevier Science S.A. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Other Chemical Sciences
Research Field:Organometallic Chemistry
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Denney, MC (Mrs Melanie Denney)
Author:Ruether, T (Dr Thomas Ruether)
Author:Cavell, KJ (Professor Kingsley Cavell)
Author:Peacock, EJ (Dr Evan Peacock)
Author:Braussaud, N (Dr Nathalie Braussaud)
ID Code:19523
Year Published:2000
Web of Science® Times Cited:60
Deposited By:Chemistry
Deposited On:2000-08-01
Last Modified:2001-03-26
Downloads:0

Repository Staff Only: item control page