The reaction of TcCl 3(Me 2PhP) 3 with dithio ligands. Synthesis, characterization and X-ray crystal structures of [TcCl 2(Me 2PhP) 2(Me 2dtp)] and [Tc(Me 2PhP)(Etxan) 3] (Me 2PhP=dimethylphenylphosphine, Me 2dtp −= O, O′-dimethyldithiophosphate, Etxan −=ethylxanthate)

Abstract

Trichlorotris(dimethylphenylphosphine)technetium(III), [TcCl 3(Me 2PhP) 3], reacts with dithio ligands to form chelate complexes of different compositions and coordination geometries. The reaction with ethylxanthate (Etxan -) yields the diamagnetic seven-coordinate [Tc(Me 2PhP)(Etxan) 3], which crystallizes monoclinic in the space group P2 1/ c with Z=4 ( a=18.44(5), b=9.2(1), c=15.36(6) Å, β=104.3(2)°). The final R value is 0.029. The metal has a pentagonal-bipyramidal environment. With ammonium dimethyldithiophosphate, (NH 4)Me 2dtp, [TcCl 3(Me 2PhP) 3] forms the paramagnetic [TcCl 2(Me 2PhP) 2(Me 2dtp)] in which the technetium atom has a distorted octahedral coordination sphere. The compound crystallizes orthorhombic, space group Pbcn, with Z=4 ( a=16.207(1), b=10.445(1), c=14.878(1)). The final R value is 0.031. The chloro ligands are in trans arrangement.