title: Direct observation of the fourth MLCT triplet state in ruthenium(II) tris(2,2'-bipyridine).
abstract: The luminescence properties of ruthenium(ii) tris(2,2'-bipyridine) have been recorded in butyronitrile solution and in a transparent KBr disk over a reasonable temperature range. In solution, spectral curve fitting routines indicate that emission arises solely from an ensemble of triplet states, each of which is of Metal-to-Ligand, Charge-Transfer (MLCT) character and of closely comparable energy. At ambient temperature, dual emission is observed for the KBr disk and interpreted in terms of luminescence from both the ensemble and the fourth MLCT triplet state that lies at slightly higher energy. Relative reorganisation energies, energies, Huang-Rhys factors and radiative rate constants have been calculated for the two emissive states. It is confirmed that the fourth MLCT triplet state possesses more singlet character than the ensemble.
authors.affiliation: Molecular Photonics Laboratory, School of Natural Sciences, University of Newcastle, Bedson Building, Newcastle upon Tyne, UK. Anthony.harriman@ncl.ac.uk
authors.forename: Anthony
authors.initials: A
authors.lastname: Harriman
authors.forename: Guillaume
authors.initials: G
authors.lastname: Izzet
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives*; D000465:Algorithms; D001965:Bromides / Q000737:chemistry; D002413:Cations, Divalent; D004735:Energy Transfer; D008024:Ligands; D009570:Nitriles / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013057:Spectrum Analysis; D013696:Temperature
chemical_list: D001965:Bromides; D002413:Cations, Divalent; D008024:Ligands; D009570:Nitriles; D017680:Potassium Compounds; D012996:Solutions; D015082:2,2'-Dipyridyl; D012428:Ruthenium; C032723:N-butyronitrile; C039004:potassium bromide