Issue 9, 1996

Equilibria and rates of olefin substitution in zerovalent palladium complexes containing a 2-pyridylmethanimine ligand

Abstract

Equilibrium constants Ke have been determined for the olefin susbtitution in palladium(0)α-diimine olefin (ol) complexes [Pd(η2-ol)(L–L)] by ol′ in chloroform [L–L = 2-NC5H4CH[double bond, length half m-dash]NC6H4OMe-4; ol = dimethyl fumarate (dmf), ol′= acrylonitrile (an), l-chloro-l-cyanoethylene, 1,4-naphthoquinone (nq), tetramethyl ethyleneteracarboxylate (tmetc), fumaronitrile (fn) or maleic anhydride (ma); ol = nq, ol′= tmetc, fn or ma]. The substitution equilibria are rapidly established except when ol = dmf, nq, ol′= tmetc and were studied by UV/VIS and 1H NMR spectrometry. The Ke values increase with increasing electron affinity of the entering activated olefin. The kinetics of slow approach to equilibrium were monitored by UV/VIS techniques at various temperatures. When ol = dmf, ol′= tmetc, only the second-order rate constant k2 for the forward step could be measured with sufficient accuracy, whereas for ol = nq, ol′= tmetc the constants for both the forward (k2) and the reverse (k–2) steps were determined. Activation parameters indicate an essentially associative mechanism for these paths.

Article information

Article type
Paper

J. Chem. Soc., Dalton Trans., 1996, 1921-1926

Equilibria and rates of olefin substitution in zerovalent palladium complexes containing a 2-pyridylmethanimine ligand

L. Canovese, F. Visentin, P. Uguagliati and B. Crociani, J. Chem. Soc., Dalton Trans., 1996, 1921 DOI: 10.1039/DT9960001921

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements