Cyclometalated RuII Complexes with Improved Octahedral Geometry: Synthesis and Photophysical Properties

Cyclometalated bis-tridentate ruthenium(II) complexes incorporating 2,6-diquinolin-8-ylpyridine ligands and exhibiting broad visible absorptions are described. A [Ru(N∧N∧N)(N∧C∧N)]+ complex based only on ligands with expanded bite angles has a metal-to-ligand charge-transfer excited-state lifetime of 16 ns, which is attributed to a strong ligand field and therefore reduced deactivation via metal-centered states.