Reactions of α-diimino ligands with the chloro-bridged dimer [RhCl(COD)]2(COD=1,5-cyclooctadiene)

Abstract The reactions of α-diimino ligands N - N ′ [ N - N ′= 2,2′-bipyridine (bipy), C 5 H 4 N2CHNR (R= C 6 H 4 OMe- p , PyCa), RNCHCHNR (R=C 6 H 4 - OMe- p , DAB)] with [RhCl(COD)] 2 give rise to stoichiometry, solvent, ligand, and temperature dependent equilibria. In general, the 1/1 ligand/dimer reaction yields the ionic product [Rh(COD)( N - N ′)] [RhCl 2 (COD)], at room temperature. For N - N ′=DAB, the ionic form is in equilibrium with the binuclear compound [{RhCl(COD)} (μ-DAB){RhCl(COD)}] (containing a σ σ,'- N , N ′ bridging α-diimine), which becomes the predominant species at low temperatures. In [Rh(COD)( N - N ′)] [RhCl 2 (COD)], a fast exchange of the Rh(COD) unit betwe…