Unusual dimer formation of cyclometalated ruthenium NHC p-cymene complexes. Issue 8 (3rd February 2016) - Schleicher, David
Abstract : Abstraction of a chloride ion in p -cymene ruthenium(ii ) complexes bearing cyclometalated NHC ligands selectively leads to the formation of mono-ion-bridged ruthenium dimers. Abstract : We present the synthesis and structural characterization of novel ruthenium complexes containing C^C* cyclometalated N -heterocyclic carbene ligands, η 6 -arene ( p -cymene) ligands and one bridging chlorine ion. Complexes of the general formula [Ru( p -cymene)(C^C*)Cl] were prepared via a one-pot synthesis using in situ transmetalation from the correspondent silver NHC complexes. These complexes react with sodium tetrakis[3, 5-bis(trifluoromethyl)phenyl]borate (NaBAr F 4 ) to form dinuclear complexes of the general structure [Ru( p -cymene)(C^C*)-μ-Cl-( p -cymene)(C^C*)Ru] + [BAr F 4 ] − . Solid-state structures confirm that the pseudo-tetrahedral coordination around the metal center with the η 6 -ligand aligned perpendicularly to the C^C* ligand and the i -Pr group "atop" is retained in the bimetallic complexes.