An oligosilane initiator for the Wurtz-type polymerisation of dichloromethylphenylsilane

Holder, Simon J. and Achilleos, Mariliz (2008) An oligosilane initiator for the Wurtz-type polymerisation of dichloromethylphenylsilane. Journal of Organometallic Chemistry, 693 (10). pp. 1938-1944. ISSN 0022-328X. (The full text of this publication is not available from this repository)

The full text of this publication is not available from this repository. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1016/j.jorganchem.2008.02.022

Abstract

1-Chloro-4-methyl-1,1,2,2,3,3,4,4-octaphenyltetrasilane was employed as an initiator in the Wurtz-type reductive coupling polymerisations of dichloromethylphenylsilane with sodium in toluene at 65 degrees C. Yields of polymethylphenylsilane (PMPS) were in the range 32-35% which was almost double that obtained by otherwise identical reactions in the absence of the initiator (16-19%). Furthermore, higher molecular weight parameters were observed for PMPS synthesised with the initiator. This is believed to be a result of the low reduction potential of the oligosilane allowing for it to compete efficiently in the initiation step with the dichloromethylphenylsilane monomer and inhibit end-biting, which usually occurs in conventional syntheses by reaction of the silyl anion with the terminal silicon-chlorine bond in the early stages of the polymerisation. Si-29 NMR spectroscopic analysis of an isolated high molecular weight fraction supported the incorporation of the oligosilane in the PMPS chain. In contrast, the use of the initiator in the Wurtz-reductive coupling of dichloromethylphenylsilane in tetrahydrofuran at room temperature led to no increase in molecular weights or yields of PMPS which confirms that the end-biting reaction is not as significant in polymerisations carried out under these conditions.

Item Type: Article
Uncontrolled keywords: polysilane; oligosilane; initiator; mechanism; polymerisation
Subjects: Q Science > QD Chemistry
Divisions: Faculties > Science Technology and Medical Studies > School of Physical Sciences > Functional Materials Group
Depositing User: Simon Holder
Date Deposited: 27 Mar 2009 17:28
Last Modified: 09 May 2014 13:59
Resource URI: http://kar.kent.ac.uk/id/eprint/11731 (The current URI for this page, for reference purposes)
  • Depositors only (login required):