Synthesen und Kristallstrukturen von Bis(N-lithiumtrimethylsilylamino)- bis(dimethylamino)silan und 1,1-Dichloro-2,4-bis(trimethylsilylamino)- 3,3-bis(dimethylamino)siladiazatitanacyclobutan / Syntheses and Crystal Structures of Bis(N-lithio-trimethylsily

Bis(N-lithio-trimethylsilylamino)bis(dimethylamino)silane (1) is formed in the reaction of silicon tetrachloride with excess hexamethyldisilazane, followed by halogen substitution using two equivalents of LiN(CH3)2, and treatment with two equivalents of n-butyllithium in hexane. 1, found to be dimeric in the solid state, was characterised by single crystal X-ray diffraction (monoclinic, C2/c, a = 1925.2(4), b = 1501.7(2), c = 1389.7(3) pm, β= 101.98(2), Z = 4, C20H60Li4N8Si6), and by solid state and solution NMR spectroscopy and mass spectrometry. Further reaction with titanium tetrachloride (molar ratio 1:1) yields orange crystals of the dimer [TiClf(μ2-NSi(CH3)3)2Si(N(CH3)2)μ2-Cl]2 (2) characterised by single crystal X-ray diffraction (triclinic, P1, a = 942.1(4), b = 991.7(4), c = 1222.6(5) pm, α= 90.12(1), β= 94.42(2), γ= 107.64(1)°, Z = 1, C20H60Cl4N8Si6Ti2)