Preparation and structure of dibromobis (N,N-diethyldithiocarbamato)-thionitrosyltechnetium(III)

A technetium compound has been prepared by the reaction of [TcN(S2CNEt2)2] with SOBr2, and its crystal structure has been determined by single-crystal X-ray diffraction methods at 23±1 deg. C. Crystals are orthorhombic, space group Pnma, with a=14.864(7), b=15.857(7), c8.938(4)Aangstroem and Z=4. Full-matrix least-squares refinement gave a final R value of 0.047 for 1685 independent reflections. The technetium atom is seven-coordinate with a distorted pentagonal-bipyramidal coordination geometry. The thionitrosyl ligand and a bromo ligand occupy the axial positions, with the thionitrosyl group exerting a small trans influence. The small amount of empirical data available to date suggests that the trans influence of the thionitrosyl ligand is comparable to that of nitrosyl although there are as yet no examples of trans shortening with thionitrosyl complexes. 43 refs., 4 tabs., 1 fig