Iminosilanes as precursors for monomeric bis(silyl)aminomethylalanes and silyliumtrichloroaluminates - Synthesis and crystal structures

The iminosilanes (Me3C),Si=NR [R=Si(CMe3)(2)C6H5; Si(CHMe2)CMe3] react with AlMe3 to give the monomeric aminodimethylalanes Me2Al-N(R)Si(CMe3)(2)Me 1 [R: Si(CMe3)(2) C6H5] and 2 [R:Si(CHMe2)(2)CMe3]. The reaction of (Me3C)(2) Si=N-Si(CMe3)(2) C6H5 and Me2AlCl affords the monomeric aminochloromethylal ane ClMeAl-N(R)Si(CMe3)(2)Me 3 [R:Si(CMe3)(2)C6H5] The aminofluorosilanes 4 and 7 react with (BuLi)-Bu-n in thf under formation of the four-membered l ithium ring derivatives (Me3C)(2)SiFN(Li (thf)(2))R 5 [R:Si(CHMe2)(2)Me] an d 8 [R:Si(CHMe3)(2)H]. (Me3C)(2)SiFN (ALMe(2))R 6 [R:Si (CHMe2)(2) Me] is o btained in reaction of the lithium derivative of 4 and Me2AlCl in n-hexane. 8 and AlCl3 form the silyliumtrichloroaluminate (Me3C)(2)Si=NR . AlCl3 9 [ R:Si(CMe3)(2)H], a four-membered ring with a bridging chlorine atom. The cr ystal structures of 1, 3, 8 and 9 have been determined. 1 crystallizes in t he space groups P2(1)/n, a = 1119.3(1), b = 1560.1(2), c = 1662.2(3) pm, be ta = 105.75(1)degrees, V = 2.7936(7) nm, rho(calcd) = 1.065 Mg/m(3), Z = 4 and 3392 independent reflections, R1(I > 2 sigma (I))= 0.035, wR2 (all data ) = 0.089, 3 in the space group P2(1)/n, a = 1115.6(1), b = 1543.8(2), c = 1669.5(2) pm, beta = 105.90(1)degrees V = 2.7653(5) nm(3), rho(calcd) = 1.1 08 Mg/m(3), Z = 4 and 4908 independent reflections, R1(I > 2 sigma (n)) = 0 .032, wR2(all data) = 0.088, 8 in the space group P2(1)/n, a = 931.2(1), b = 1668.1(2), c = 1950.5(3) pm, beta = 97.86(1)degrees, V = 3.0013(7)nm(3), rho(calcd) = 1.040 Mg/m(3), Z = 4 and 3914 independent reflections, R1(I > 2 sigma (I)) = 0.044, wR2(all data) = 0.122, and 9 in the space group P2(1) /c, a = 1345.1(2), b = 1001.5 (2), c = 1855.1 (3) pm, beta = 108.61(2)degre es, V = 2.3684(7) nm(3), rho(calcd) = 1.214 Mg/m(3) Z = 4 and 3080 independ ent reflections, R1 (I > 2 sigma (I)) = 0.052, wR2(all data)= 0.117.