Synthesis of RhIII and IrIII Complexes Bearing Chelating Di-NHC Ligands Obtained from N9-Imidazolium-Substituted Adenine

The N9-imidazolium-substituted adenine derivative H- 1 Cl reacts with [MCl 2 (Cp*)] 2 (M = Rh, Ir) in acetonitrile at 75 °C with formation of the C NHC ^N3 adenine chelate complexes [ 3 ]Cl and [ 4 ]Cl, respectively. At higher temperature (125 °C), double deprotonation of H- 1 Cl by NaOAc was observed and the reaction with [MCl 2 (Cp*)] 2 (M = Rh, Ir) yields the chelate complexes [ 5 ] and [ 6 ] bearing a unique C NHC ^C azolato chelate ligand. The N7-protonation of the ring-nitrogen atoms of the azolato donor in [ 5 ] and [ 6 ] was also performed to give the complexes bearing a C NHC ^C pNHC chelate ligand.