The Preparation and Stereochemistry of Optically Active Cobalt(III) Complexes with 3,3′-Dimethyl-2,2′-bipyridine and Bis(diamines) or Tetramines

Abstract Bis(en), trien, tren and bis(R,R-chxn) cobalt(III) complexes of 3,3′-dimethyl-2,2′-bipyridine (dmbpy) have been prepared and resolved. The dissymmetric conformation of dmbpy arising from the non-coplanarity of the two pyridine rings is maintained in the inert complexes. 3,3′-Dimethyl-2,2′-bipyridine coordinates to the cobalt(III) ion with a stereospecific conformation depending on the configuration. The absorption and circular dichroism (CD) spectra of the dmbpy complexes were compared with those of the corresponding 2,2′-bipyridine (bpy) complexes.