Issue 30, 2013

Pentacoordinate silicon complexes with dynamic motion resembling a pendulum on the SN2 reaction pathway

Abstract

A series of glutarimide derivatives which has two carbonyl coordination sites for intramolecular pentacoordination at silicon with a X1+nSiC3−nO moiety have been synthesised and characterized. The substituent (leaving group) effects on the Si–O bond exchange between the two coordination sites (resembling a pendulum) have been studied by comparison of the differently substituted (X = F, Cl, OTf, Br and I) structures. The activation parameters for the Si–O bond exchange process were measured by NMR and separately computed and are consistent with the strength of Si–O bond coordination and the nature of the leaving group, X. The temperature-dependent 29Si NMR spectroscopy is supported by X-ray crystallography and shows that the tetrahedral reactant is converted into pentacoordinate intermediates by intramolecular O–Si association followed by reversion to a tetrahedral geometry by Si–X dissociation. The two association/dissociation patterns offer a model for nucleophilic substitution at a silicon atom. A continuum of structures on the SN2 reaction profile from the glutarimide derivatives correlates reasonably well with the structural data obtained from derivatives of lactams, diketopiperazines and quinolones.

Graphical abstract: Pentacoordinate silicon complexes with dynamic motion resembling a pendulum on the SN2 reaction pathway

Supplementary files

Article information

Article type
Paper
Submitted
06 Mar 2013
Accepted
21 May 2013
First published
22 May 2013

Dalton Trans., 2013,42, 10971-10981

Pentacoordinate silicon complexes with dynamic motion resembling a pendulum on the SN2 reaction pathway

M. Sohail, R. Panisch, A. Bowden, A. R. Bassindale, P. G. Taylor, A. A. Korlyukov, D. E. Arkhipov, L. Male, S. Callear, S. J. Coles, M. B. Hursthouse, R. W. Harrington and W. Clegg, Dalton Trans., 2013, 42, 10971 DOI: 10.1039/C3DT50613D

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.

Social activity

Spotlight

Advertisements