Determination of the molecular structure of tris(trimethylsilyl)amine in the gas phase by electron diffraction

Abstract

The structure and conformation of tris(trimethylsilyl)amine in the gas phase have been determined by electron diffraction. The three Si–N bonds are coplanar and 175.5(3) pm long (r_a). The trimethylsilyl groups are arranged so that the overall symmetry for the heavy atoms is very close to C_3h, with twists of just 5.2(24)° reducing the symmetry to C₃. The errors in parentheses are each one standard deviation, so this torsional distortion is barely significant. The trimethylsilyl groups had local C_s symmetry, with two NSiC angles of 111.5(7) and one of 112.6(4)°, and two CSiC angles 108.0(8)° and the other one thus 105.0°. Other major parameters are r(Si–C) 187.9(3) pm, r(C–H) 110.6(3) pm, and SiCH 110.1(4)°.