Syntheses and properties of phosphine-substituted ruthenium(ii) polypyridine complexes with nitrogen oxides

Abstract

Four novel phosphine-substituted ruthenium(II) polypyridine complexes with nitrogen oxides—trans(P,NO₂)-[Ru(trpy)(Pqn)(NO₂)]PF₆ (trans-NO₂), cis(P,NO₂)-[Ru(trpy)(Pqn)(NO₂)]PF₆ (cis-NO₂), [Ru(trpy)(dppbz)(NO₂)]PF₆ (PP-NO₂), and cis(P,NO)-[Ru(trpy)(Pqn)(NO)](PF₆)₃ (cis-NO)—were synthesised (trpy = 2,2′:6′,2′′-terpyridine, Pqn = 8-(diphenylphosphanyl)quinoline, and dppbz = 1,2-bis(diphenylphosphanyl)benzene). The influence of the number and position of the phosphine group(s) on the electronic structure of these complexes was investigated using single-crystal X-ray structural analysis, UV-vis absorption spectroscopy, and electrochemical measurements. The substitution lability of the nitrogen oxide ligand of each complex is discussed in comparison with that of the corresponding acetonitrile complexes.