TY - JOUR
T1 - Rigid biimidazole ancillary ligands as an avenue to bright deep blue cationic iridium(III) complexes
AU - Henwood, Adam Francis
AU - Evariste, Sloane
AU - Slawin, Alexandra Martha Zoya
AU - Zysman-Colman, Eli
N1 - EZ-C acknowledges the University of St Andrews for financial support.
Date of Acceptance: 03/06/2014
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Herein we report the synthesis and optoelectronic characterisation of three deep blue-emitting cationic iridium complexes, of the form [Ir(dFppy)2(N^N)]PF6, bearing biimidazole-type N^N ancillary ligands (dFppyH = 2-(2,4-difluorophenyl)pyridine). Complex 1 contains the parent biimidazole, biim, while 2 contains a dimethylated analog, dMebiim, and 3 contains an ortho-xylyl-tethered biimidzole, o-xylbiim. We explore a strategy of tethering the biimidazole in order to rigidify the complex and increase the photoluminescent quantum yield, culminating in deep blue (λmax: 457 nm in MeOH at 298 K) ligand-centered emission with a very high photoluminescent quantum yield of 68% and microsecond emission lifetime. Density functional theory calculations elucidate the origin of such disparate excited state kinetics across this series, especially in light of virtually identical optoelectronic properties observed for these compounds.
AB - Herein we report the synthesis and optoelectronic characterisation of three deep blue-emitting cationic iridium complexes, of the form [Ir(dFppy)2(N^N)]PF6, bearing biimidazole-type N^N ancillary ligands (dFppyH = 2-(2,4-difluorophenyl)pyridine). Complex 1 contains the parent biimidazole, biim, while 2 contains a dimethylated analog, dMebiim, and 3 contains an ortho-xylyl-tethered biimidzole, o-xylbiim. We explore a strategy of tethering the biimidazole in order to rigidify the complex and increase the photoluminescent quantum yield, culminating in deep blue (λmax: 457 nm in MeOH at 298 K) ligand-centered emission with a very high photoluminescent quantum yield of 68% and microsecond emission lifetime. Density functional theory calculations elucidate the origin of such disparate excited state kinetics across this series, especially in light of virtually identical optoelectronic properties observed for these compounds.
UR - http://www.rsc.org/suppdata/fd/c4/c4fd00107a/c4fd00107a1.pdf
UR - http://www.rsc.org/suppdata/fd/c4/c4fd00107a/c4fd00107a2.cif
U2 - 10.1039/C4FD00107A
DO - 10.1039/C4FD00107A
M3 - Article
SN - 1359-6640
VL - 174
SP - 165
EP - 182
JO - Faraday Discussions
JF - Faraday Discussions
ER -