Rui Liu, Naveen K. Dandu, Jinquan Chen
Sep 25, 2014
Citations
0
Influential Citations
36
Citations
Journal
Journal of Physical Chemistry C
Abstract
Four heteroleptic cationic iridium(III) complexes containing cyclometalating 2-{3-[7-(benzothiazol-2-yl)fluoren-2-yl]phenyl}pyridine ligand and different diimine (N∧N) ligands (N∧N = 2-(pyridin-2-yl)quinoline (1), 1,10-phenanthroline (2), 2,2′-biquinoline (3), and 1,1′-biisoquinoline (4)) and a reference complex bearing 2-(pyridin-2-yl)quinoline and 2-phenylpyridine ligands (5) were synthesized and characterized. The influence of the diimine (N∧N) ligand on the photophysics of these complexes has been systematically investigated via spectroscopic methods and by time-dependent density functional theory (TDDFT). All complexes exhibit N∧N or C∧N ligand localized 1π,π* transitions below 400 nm, and broad and structureless metal-to-ligand and ligand-to-ligand charge transfer (1MLCT/1LLCT) absorption bands between 400 and 450 nm, and weak 3MLCT/3LLCT absorption above 450 nm. Increasing the π-conjugation of the N∧N ligand causes enhanced molar extinction coefficients of the absorption bands and a bathochromic sh...