Attachment of the New Bulky Ligand (Me3Si)2(Me2NMe2Si)C to Li Hg Al Ga and Sn. Crystal Structures of [Li\{C(SiMe3)2(SiMe2NMe2)\}(THF)2] [Hg\{C(SiMe3)2(SiMe2NMe2)\}2] [Al\{C(SiMe3)2(SiMe2NMe2)\}X2] (X=Cl Ph) and [Ga\{c(SiMe3)2(SiMe2NMe2)\}Cl2]

The organolithium reagent (1) is readily obtained by reaction of the chloride (Me3Si)2(Me2NMe2Si)CCl with LiBu in THF (tetrahydrofuran) at low temperature. Reactions of 1 with HgBr2, AlCl3, GaCl3, and SnCl4 give [Hg{C(SiMe3)2(SiMe2NMe2)}2] (2), (3), Ga{C(SiMe3)2(SiMe2NMe2)}Cl2 (5), and [Sn{C(SiMe3)2(SiMe2NMe2)}Cl3] (6), respectively, and treatment of 3 with LiPh gives (4). Crystal structure determinations have shown that there is intramolecular coordination of the N atom to the metal M, with formation of a planar four-membered ring, in 1, 3, 4, and 5 (but not 2). Engagement of the lone pair on N in coordination with Al in 3 results in an exceptionally long Si−N bond length of 1.875(2) A, some 0.16 A longer than that in 2 and in simple silylamines generally; the Si−N bond is possibly shorter in 4 (1.851(2) A) and 5 (1.858(4) A), and is markedly so in 1 (1.796(4) A), but still notably long. The lengths of the N−metal bonds in these compounds are similar to those between alkylamines and the metals in coordin...