Synthesis and circular dichroism characterization of new optically active transition metal complexes:M[(-)bdtp]3, M = Co3+, Rh3+, Ir3+

The chiral octahedral diastereoisomeric tris[(-)cyclic O,O’,1(R),2(R)(-)dimethylethylene dithiophosphato]metal(III) complexes, M[(-)bdtp]3, M(III) = Co, Rh, Ir, have been obtained stereoselectively in the Λ or Δ absolute configuration at the metal centre. The formation reaction and the characterization of the obtained complexes have been followed by circular dichroism spectroscopy. The complexes prove optically labile in various solvents. A configuration inversion has been observed in all complexes giving diastereoisomeric equilibria Λ(R,R)(R,R)(R,R) = Δ(R,R)(R,R)(R,R) with an excess of one form, occasionally stabilized by the solvent.