Crystal and molecular structure of tris[bis(trimethylsilyl)amino]aluminium, Al[N(SiMe3)2]3

The crystal structure of Al[N(SiMe3)2]3 has been determined by single-crystal X-ray diffraction. The crystals are trigonal, space group P1c, with Z= 2 in a unit cell of dimensions a= 15·950 ± 0·009, c= 8·683 ± 0·017 Å. The molecule has D3 symmetry with a dihedral angle of 50° between the AlN3 and AlNSi2 planes. The bond lengths and angles were found to be: Al–N 1·78 ± 0·02, N–Si 1·75 ± 0·01, mean Si–C 1·90 ± 0·02 Å, Al–N–Si 121 ± 1, mean N–Si–C 112 ± 2°.