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Competing reaction mechanisms for the carbonylation of neutral palladium(II) complexes containing bidentate ligands: a theoretical study

Citation

Frankcombe, KE and Cavell, KJ and Yates, BF and Knott, RB, Competing reaction mechanisms for the carbonylation of neutral palladium(II) complexes containing bidentate ligands: a theoretical study, Organometallics, 16, (14) pp. 3199-3206. ISSN 0276-7333 (1997) [Refereed Article]

DOI: doi:10.1021/om970063z

Abstract

The complete carbonylation mechanism for the model palladium(II) system, Pd(PH3)(CH3)-(N-O) + CO → Pd(PH3)(COCH3)(N-O) (N-O = NHCHCOO-), has been investigated employing nonlocal density functional theory (DFT) and second-order Mø11er-Plesset perturbation theory (MP2). Four possible mechanisms were identified, all involving the initial displacement of the phosphine ligand by carbon monoxide via a trigonal bipyramidal transition structure. Of these four mechanisms, the rate-determining methyl migration step was found to be lowest in energy when proceeding from a novel five-coordinate intermediate in which the palladium-nitrogen bond is weakened (2.385 Å at the MP2 level of theory). This mechanism is consistent with the available experimental data. MP2 calculations using large basis sets predicted an overall exothermicity of -59.7 kJ/mol and a negligible activation energy of +6.0 kJ/mol with respect to the separated reactants. In addition, a novel transition structure that accounts for the isomerization of square-pyramidal d8 complexes is presented.

Item Details

Item Type:Refereed Article
Research Division:Chemical Sciences
Research Group:Theoretical and Computational Chemistry
Research Field:Theoretical and Computational Chemistry not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Chemical Sciences
Author:Frankcombe, KE (Ms Katrina Ellen Frankcombe)
Author:Cavell, KJ (Professor Kingsley Cavell)
Author:Yates, BF (Professor Brian Yates)
ID Code:11939
Year Published:1997
Web of Science® Times Cited:25
Deposited By:Chemistry
Deposited On:1997-08-01
Last Modified:2011-08-15
Downloads:0

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