Strained Ruthenium Complexes Bearing Tridentate Guanidine?Derived Ligands

The dimer [{(?6-p-cymene)RuCl}2(?-Cl)2] (cymene=MeC6H4iPr) reacts with N,N?-bis(p-tolyl)-N??-(2-pyridinylmethyl)guanidine (H2L1) and N,N?-bis(p-tolyl)-N??-(2-diphenylphosphanoethyl)guanidine (H2L2), in the presence of NaSbF6, giving rise to chlorido compounds formula [(?6-p-cymene)RuCl(H2L)][SbF6] (H2L=H2L1 (1), H2L2 (2)) which guanidine ligand adopts a ?2 chelate coordination mode. related (S)-N,N?-bis(p-tolyl)-N??-(1-isopropyl, 2-diphenylphosphano ethyl)guanidine (H2L3) affords mixtures corresponding compound [(?6-p-cymene)RuCl(H2L3)][SbF6] (3) together complexes [(?6-p-cymene)RuCl2(H3L3)][SbF6] (4) [(?6-p-cymene)Ru(?3N,N?,P-HL3)][SbF6] (10) contain phosphano-guanidinium phosphano-guanidinate ions acting as monodentate tridentate ligand, respectively. Compounds 1, 2 mixture 3/4/10 react AgSbF6 rendering cationic aqua-complexes [(?6-p-cymene)Ru(H2L)(OH2)][SbF6]2 (5), (6), H2L3 (7)). These exhibit temperature-dependent fluxional process solution. Experimental NMR studies DFT theoretical calculations on complex 6 suggest that involves exchange between two rotamers around one C?N bonds. Treatment 5–7 NaHCO3 renders [(?6-p-cymene)Ru(?3N,N?,N??-HL1)][SbF6] (8) [(?6-p-cymene)Ru(?3N,N?,P-HL)][SbF6] (HL=HL2 (9), HL3 (10)), respectively, HL fac ?3 new have been characterized by analytical spectroscopic means, including determination crystal structures 2, 5, 9 10, X-ray diffractometric methods.