Coordination behavior of some bridge ligands having S–O bond bound to four-membered ring unit (Ru2O2) of dinuclear areneruthenium complexes

Visible light irradiation of cis -azobenzene bridging dinuclear η6-areneruthenium complex [Ru2(η6:η1-C6H5CH2CH2CH2O)2(cis -PhN = NC6H4OMe-p)](BF4)2 in the presence of excess DMSO led to precipitation of a new dinuclear complex containing 1 equiv. DMSO ligand, [Ru2(η6:η1-C6H5CH2CH2CH2O)2(DMSO)](BF4)2 (6). A single crystal X-ray structural study of 6 revealed the presence of bridging DMSO ligand which uses O and S atoms as the donor. Treatment of 6 with 1 and 2 equiv. NaBArf (BArf = B[C6H3(CF3)2-2,5]4) afforded [Ru2(η6:η1-C6H5CH2CH2CH2O)2(DMSO)](BF4)(BArf) and [Ru2(η6:η1-C6H5CH2CH2CH2O)2(DMSO)](BArf)2, respectively, although the former was not isolated but assumed to exist only in solution by conductivity measurements. A neutral dinuclear areneruthenium complex with a bridging View the MathML sourceSO42- ligand, [Ru2(η6:η1-C6H5CH2CH2CH2O)2(SO4)] was prepared from the hydroxide [Ru2(η6:η1-C6H5CH2CH2CH2O)2(OH)]BF4 and [Et3NH](HSO4). The View the MathML sourceSO42- ion in this complex coordinates to dicationic Ru2 center rather strongly in CH2Cl2, while in MeOH the complex lies in equilibrium with a complex formed by methanolysis reaction, namely methoxy bridging dinuclear complex [Ru2(η6:η1-C6H5CH2CH2CH2O)2(OMe)]+View the MathML source