Synthesis and electronic characterization of bipyridine dithiolate rhodium(III) complexes

Inorg Chem. 2005 Nov 28;44(24):8804-9. doi: 10.1021/ic051171d.

Abstract

Five new mixed diimine 1,1'-dithiolate or dithiocarbamate ligand complexes of the form [Rh(bpy)2(SS)][PF6]n, where bpy = 2,2'-bipyridine and SS = various substituted dialkyldithiocarbamates or 1,1'-dithiolates, were synthesized from cis-[Rh(bpy)2(OTf)2][OTf]. The triflate ligands are easily displaced by other ligands and allow these syntheses to proceed in high yields (80-90% overall) under relatively mild reaction conditions and to give high purity products. Electrochemistry shows irreversible two-electron reduction of Rh(III) to Rh(I) and a concomitant loss of one bipyridine ligand; this is followed by reversible one-electron reduction of the remaining 2,2'-bipyridine ligand. The electronic characterizations of these complexes are consistent with significant delocalization of the sulfur electron density onto the empty metal d orbitals. The 1,1'-dithiolate ligands induce larger red shifts in the absorption and emission spectra than the dithiocarbamates as the 1,1'-dithiolates have a more extensive conjugation system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemistry, Inorganic / methods*
  • Electrochemistry / methods
  • Magnetic Resonance Spectroscopy
  • Pyridines / chemical synthesis
  • Pyridines / chemistry*
  • Rhodium / chemistry*

Substances

  • Pyridines
  • Rhodium