Aluminum hydride cations stabilized by weakly coordinating carbaalanates

Abstract

The reactions of t-BuC &3bond; CLi with a mixture of AlH(3)center dot NMe3 and ClAlH(2)center dot NMe3 in boiling toluene with the addition of [t-BuCH2(Bzl)NMe2]Cl, or a bulky beta-diketimine instead, and [n-Bu4N]Cl led to the carbaalanates [H2Al(NMe3)(2)](2)center dot[(AlH)(8)(CCH(2)t-Bu)(6)], 3, and [n-Bu4N](2)[(AlH)(8)(CCH(2)t-Bu)(6)], 4, respectively. The reaction of Me3N center dot Al(C equivalent to Ct-Bu)(3) 5 and AlH(3)center dot NMe3 in boiling toluene yielded [H(n-Bu)Al(NMe3)(2)][(AlH)(7)(AlNMe3)(CCH(2)t-Bu)(6)], 6, in trace amounts, The single-crystal X-ray structures of 3 and 6 are reported. The compounds 3, 4, and 6 consist of well-separated ion pairs introducing carbaalanates as weakly coordinating anions and stabilizing aluminum hydride cations.