BIROn - Birkbeck Institutional Research Online

    Investigation of a spiro to ansa rearrangement with di-functional alcohols in cyclotriphosphazene derivatives

    Beşli, S. and Coles, Simon J. and Susanne Coles, L. and Davies, David B. and Kiliç, A. (2012) Investigation of a spiro to ansa rearrangement with di-functional alcohols in cyclotriphosphazene derivatives. Polyhedron 43 (1), pp. 176-184. ISSN 0277-5387.

    Full text not available from this repository.

    Abstract

    A spiro to ansa rearrangement has been investigated by the reactions of cyclotriphosphazene derivatives having five-membered spiro rings, N3P3Cl4[O(CH2)2NH], (1) and N3P3Cl4[O(CH2)2O], (2) with disodium salts of 1,3-propanediol and 2,2,3,3-tetrafluoro-1,4-butanediol. Compounds 1 and 2 with the strong nucleophile, 1,3-propapanediol, give rearrangement reactions to form stable ansa-ansa compounds, whereas reaction of compounds 1 and 2 with the fluorinated alkoxide results in normal nucleophilic substitution at the PCl2 groups and no rearrangement takes place with the weaker nucleophile. The synthesised compounds (3a, 3b, 4b, 5a-d, 6c and 6d), have been fully characterised by elemental and mass (MS) analysis, and by 1H and 31P NMR spectroscopy. Crystal structures of 3b, 4b, 5b, 5c, 5d and 6c have been characterised by X-ray crystallography. It is found that 1,3-propapanediol is a sufficiently strong nucleophile to cause a spiro to ansa rearrangement in the mono-spiro cyclotriphosphazenes compounds 1 and 2, even though crystallographic evidence shows that formation of the seven- and eight-membered ansa-ansa rings in compound 3b results in distortion and compression of the cyclophosphazene ring. A possible mechanism, which depends on attack of the anionic oxygen nucleophile at spiro-bearing phosphorus atom, was used to help understand the spiro-to-ansa rearrangement reaction.

    Metadata

    Item Type: Article
    Keyword(s) / Subject(s): Cyclotriphosphazenes, Molecular rearrangement, Crystal structures, N3P3 ring distortions, Mechanism
    School: Birkbeck Schools and Departments > School of Science > Biological Sciences
    Depositing User: Administrator
    Date Deposited: 18 Jun 2012 13:06
    Last Modified: 20 Oct 2014 13:33
    URI: http://eprints.bbk.ac.uk/id/eprint/4821

    Statistics

    Downloads
    Activity Overview
    0Downloads
    126Hits

    Additional statistics are available via IRStats2.

    Archive Staff Only (login required)

    Edit/View Item Edit/View Item