PREPARATION AND STRUCTURE OF DIBROMOBIS(N,N-DIETHYLDITHIOCARBAMATO)-THIONITROSYLTECHNETIUM(III)

The title compound, [Tc(NS)(S2CNEt2)2Br2], 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-degrees-C. Crystals are orthorhombic, space group Pnma, with a 14.864(7), b 15.857(7), c 8.938(4) angstrom, 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 with Tc-Br(trans) 2.595(1) and Tc-Br(cis) 2.564(1) angstrom. The coordination of the thionitrosyl group is essentially linear with Tc-N=S 177.2(7)-degrees, Tc-N 1.754(9), and N = S 1.504(9) angstrom.