| Abstract
| - Treatment of the phosphine-borane adduct (Me3Si)2{Me2P(BH3)}CH (5) with either MeNa or MeK indiethyl ether yields the corresponding alkali metal salts [[(Me3Si)2{Me2P(BH3)}C]ML]∝ [ML =Na(THF)2·1/2PhMe (6a); K (7)] after recrystallization. Metathesis reactions between in situ prepared[(Me3Si)2{Me2P(BH3)}C]Li and either rubidium or cesium 2-ethylhexoxide give the compounds [[(Me3Si)2{Me2P(BH3)}C]ML]n [ML = Rb, n = ∞ (10); Cs(pmdeta), n = 2 (11)] after recrystallization.Compounds 6a, 7, 10, and 11 are the first heavier alkali metal complexes of a phosphine-borane-stabilizedcarbanion to be isolated in the solid state. Compounds 5, 6a, 7, 10, and 11 have been characterized byelemental analyses, multielement (1H, 13C{1H}, 11B{1H}, and 31P{1H}) NMR spectroscopy, and X-raycrystallography. In the solid state compounds 6a, 7, 10, and 11 adopt dimeric or polymeric structures inwhich the alkali metal cations are associated with both the carbanion centers and the borane hydrogenatoms.
- The first structurally characterized heavier alkali metal complexes of a phosphine-borane-stabilized carbanion are reported; these compounds crystallize as dimeric or polymeric aggregates.
|
