Crystal and molecular structure of C, N-{2-[(dimethylamino)methyl]phenyl} diphenyltin bromide

Abstract

The crystal and molecular structure of C, N-{2-[(dimethylamino)methyl]phenyl}diphenyltin bromide 2-Me 2 NCH 2C 6H 4Sn Ph 2Br have been determined by a single-crystal X-ray diffraction study. Crystals are monoclinic, space group P2 1/ c with Z  4 in a unit cell of dimensions: a  8.609(1), b  15.470(2), c  17.149(4) Å and β  117-79(2)°. The heavy atom positions were determined by direct methods while the other atoms were located by standard Fourier techniques. The structure was refined by block-diagonal least-squares techniques to a final R value of 0.060 for 2875 reflections. The tin atom has a distorted trigonal bipyramidal geometry, with the Me 2NCH 2C 6H 4 group spanning one equatorial and one axial site. The two phenyl groups reside in the two remaining equatorial positions while the bromine atom occupies an axial site. The axial bond lengths are: SnN(ax) 2.51 Å and SnBr(ax) 2.63 Å while the NSnBr bond angle amounts to 171°. The acute C(13)SnN bond angle in the five-membered chelate ring, which is puckered at the C( sp 3) N and Sn atoms, is 75.3°. The present structure provides the first example of a triorganotin halide containing a pentacoordinate tin atom as a result of intramolecular coordination with a built-in ligand.