Inorganic Chemistry, Vol.50, No.19, 9454-9464, 2011
Tetrylenes Chelated by Hybrid Amido-Amino Ligand: Derivatives of 2-[(N,N-Dimethylamino)methyl]aniline
Reaction of 2-[(dimethylamino)methyl]aniline with butyllithium, followed by conversion with triinethylsilyl, triphenylsilyl, triphenylgermyl, trimethylstannyl, or tri-n-butyl-stannyl chloride, gives the corresponding substituted aniline. These compounds were further deprotonated by butyllithium and reacted with germanium, tin, and lead dichlorides, respectively, in both stoichiometric ratios 2:1 and 1:1, providing the target homo- ([2-(Me2NCH2)C6H4(YR3)N](2)M) and heteroleptic ([2-(Me2NCH2)C6H4(YR3)N]MCl) germylenes and stannylenes, where M = Ge, Sn, Y = Si, Ge, and R = Me, Ph. Unlike all of these cases, the heteroleptic plumbylene can only be obtained with this reaction when the amide is substituted by a trimethylsilyl moiety. Anilines substituted by trimethyltin or tri-n-butyltin moieties gave transmetalation products after the second deprotonation by butyllithium. The trimethyltin-substituted stannylenes could likewise not be obtained by hexamethyldisilazane elimination of (trimethylstannyl)-2-[(dimethylamino)methyl]aniline with 0.5 mol equiv of either bis[bis(trimethylsilyl)amido]tin or bis[bis(trimethylsilyl)amido]tin chloride}. Products of these reactions are heterocubanes with compositions {[2-(Me2NCH2)C6H4N]Sn}(4) and [2-(Me2NCH2)C6H4N](2)-(mu(2)-SnMe2)(2), respectively, and Me4Sn or Me3SnCl. The structures of trimethylsilyl- and triphenylgermyl-substituted germylenes, stannylenes, and plumbylenes, as well as a number of their precursors, in the crystalline state, were investigated by X-ray diffraction and NMR spectroscopy in solution. Density functional theory methods were used for evaluation of the structures of several compounds.