title: Physicochemical studies of green phosphorescent light-emitting materials from cyclometalated heteroleptic iridium(III) complexes.
abstract: A series of novel imidazole ligands were synthesized and characterized. Phosphorescence studies of series of heteroleptic cyclometalated iridium(III) complexes reveal that these complexes possess dominantly (3)MLCT and (3)π-π* excited states and the solvent shifts of these complexes are interpreted by Richardt-Dimroth and Marcus solvent functions. The results consistent with prior assignments on the absorption band to a metal-to-ligand charge transfer excited state associated with chelating ligand. Emission kinetic studies exploited that the radiative transition (k(r)), increases with increasing λ(em) and linear correlation exists between ln(k(nr)) and energy gap. Electronic transition theory is applied to study the effect of E(g) and ΔQ(e) on non-radiative transition (k(nr)). With a larger ΔQ(e), favouring vibrational overlap and leading to a larger value for k(nr).
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India. jtchalam2005@yahoo.co.in
authors.forename: Jayaraman
authors.initials: J
authors.lastname: Jayabharathi
authors.forename: Venugopal
authors.initials: V
authors.lastname: Thanikachalam
authors.forename: Natesan
authors.initials: N
authors.lastname: Srinivasan
authors.forename: Marimuthu Venkatesh
authors.initials: MV
authors.lastname: Perumal
mesh_terms: D004583:Electrons; D007093:Imidazoles / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D007700:Kinetics; D008163:Luminescent Measurements; D008739:Methyl Green; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D007093:Imidazoles; D009942:Organometallic Compounds; D007495:Iridium; C029899:imidazole; D008739:Methyl Green