Rhodium(iii) and ruthenium(ii) complexes of redox-active, chelating N-heterocyclic carbene/thioether ligands

Agnès Labande (1) , Jean-Claude Daran (1) , Nicholas J. Long (2) , Andrew J. P. White (2) , Rinaldo Poli (1, 3)

1 LCC - Laboratoire de chimie de coordination
2 Department of Chemistry [Imperial College London]
3 IUF - Institut universitaire de France

Half-sandwich rhodium(III) and ruthenium(II) complexes bearing a new redox-active ferrocenyl NHC–thioether ligand have been prepared. The synthesis of ferrocenyl thioether-imidazolium salts 3a and 3b was carried out via intermediate 2 using an improved procedure. Rhodium(III) complex 4 and ruthenium(II) complex 5 were obtained in good yields and were fully characterised by NMR spectroscopy, X-ray diffraction analysis and electrochemistry. Complex 4 shows a complex ABCD system by 1H NMR, which denotes conformational rigidity due to the presence of several bulky groups. Electrochemical analysis by cyclic voltammetry reveals reversible redox behaviour about the iron centre in 4 and 5, and indicates electronic communication between iron and rhodium or ruthenium.

Domaines: Chimie de coordination

Agnès Labande, Jean-Claude Daran, Nicholas J. Long, Andrew J. P. White, Rinaldo Poli. Rhodium(iii) and ruthenium(ii) complexes of redox-active, chelating N-heterocyclic carbene/thioether ligands. New Journal of Chemistry, 2011, 35 (10), pp.2162-2168. ⟨10.1039/C1NJ20224C⟩. ⟨hal-03157949⟩