AN UNUSUAL ALKYLTRIHYDROALUMINATE - CRYSTAL-STRUCTURES OF [ALH2(C(SIME3)(2)(SIME2OME))(MU-H)LI(THF)], [ALCL2(C(SIME2OME)(SIME3)(2)(THF)], AND [LI(C(SIME2OME)(SIME3)(2))(THF)(2)] (THF = TETRAHYDROFURAN)

Reaction of the organolilitiun reagent [Li-{C(SiMe2OMe)(SiMe3)(2)}(THF )(2)] (THF = tetrahydrofuran), 1, with LiAlH4 gave the title organotri hydridoaluminate, 2, which is unusual for an alkali metal organotrihyd ridoaluminate in being monomeric and in having the Al linked to the Li not only through hydride but also through another of its ligands. The corresponding reaction with AlCl3 gave the title organoaluminum dichl oride. The Si-O bonds in 1 and 2 are not significantly lengthened by t he O-metal coordination. The bond from Li to the OMe in 1 oxygen is no t significantly different in length from that to the THF oxygen.