Synthesis, structure, and dynamic behaviour of transition metal chelate complexes with atropisomeric dithioether ligands

The preparation and characterization of RhI, PdII, and PtII complexes with chiral C2-symmetrical dithioether ligands derived from 1,1′-binaphthalene-2,2′-dithiol (BINAS) are reported. All complexes are fluxional in solution at room temp. Interconversion between the stereoisomers can take place through conformational equilibration of the chelate ring, and/or inversion of configuration at the stereogenic sulfur. In the solid state the palladium derivative of Me2BINAS shows a twisted chair conformation of the chelate ring, with both methyl groups in equatorial positions.