title: Alkali metal complexes of sterically hindered mono- and di-carbanions containing Si-O bonds.
abstract: The oxygen-bridged, silicon-substituted alkane {(Me3Si)2CH(SiMe2)}2O (1) may be prepared by the reaction of {(Me3Si)2CH}Li with ClSiMe2OSiMe2Cl in refluxing THF. Similarly, the alkane {(Me3Si)(Me2MeOSi)CH(SiMe2CH2)}2 (2) is readily accessible from the reaction between {(Me3Si)(Me2MeOSi)CH}Li and ClSiMe2CH2CH2SiMe2Cl under the same conditions. Compound 1 reacts with two equivalents of MeK to give the polymeric complex [[{(Me3Si)2C(SiMe2)}2O]K2(OEt2)]infinity [5(OEt2)] after recrystallisation. Treatment of 2 with two equivalents of either MeLi or MeK gives the corresponding complexes [{(Me3Si)(Me2MeOSi)C(SiMe2CH2)}2Li][Li(DME)3] [7(DME)3] and [{(Me3Si)(Me2MeOSi)C(SiMe2CH2)}2K2]n (8), respectively, after recrystallisation. Treatment of the alkane (Me3Si)2(Me2MeOSi)CH with one equivalent of MeK gives the polymeric complex [{(Me3Si)2(Me2MeOSi)C}K]infinity (3). These compounds have been identified by 1H and 13C{1H} NMR spectroscopy and elemental analyses and compounds 5(OEt2), 7(DME)3 and 3 have been further characterised by X-ray crystallography. Compound 7(DME)3 crystallises as a solvent-separated ion pair, whereas 5(OEt2) and 3 adopt polymeric structures in the solid state.
authors.affiliation: Department of Chemistry, School of Natural Sciences, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: Lyndsey J
authors.initials: LJ
authors.lastname: Bowman
authors.forename: Keith
authors.initials: K
authors.lastname: Izod
authors.forename: William
authors.initials: W
authors.lastname: Clegg
authors.forename: Ross W
authors.initials: RW
authors.lastname: Harrington
authors.forename: J David
authors.initials: JD
authors.lastname: Smith
authors.forename: C
authors.initials: C
authors.lastname: Eaborn