TY - JOUR
T1 - Cationic iridium(III) complexes bearing ancillary 2,5-dipyridyl(pyrazine) (2,5-dpp) and 2,2 ':5 ',2 ''-terpyridine (2,5-tpy) ligands
T2 - synthesis, optoelectronic characterization and light-emitting electrochemical cells
AU - Hasan, Kamrul
AU - Donato, Loic
AU - Shen, Yulong
AU - Slinker, Jason D.
AU - Zysman-Colman, Eli
PY - 2014/9/28
Y1 - 2014/9/28
N2 - Four cationic iridium(III) complexes of the form [Ir(C^N)2(N^N)]+ bearing either a 2,5-dipyridylpyrazine (2,5-dpp) or a 2,2′:5′,2′′-terpyridine (2,5-tpy) ancillary ligand and either 2-phenylpyridine (ppy) or a 2-(2,4-difluorophenyl)-5-methylpyridine (dFMeppy) cyclometalating ligands were synthesized. The optoelectronic properties of all complexes have been fully characterized by UV-visible absorption, cyclic voltammetry and emission spectroscopy. The conclusions drawn from these studies have been corroborated by DFT and TDDFT calculations. The four complexes were assessed as emitters in light-emitting electrochemical cells. Complex 1a, [Ir(ppy)2(2,5-dpp)]PF6, was found to be a deep red emitter (666 nm) both in acetonitrile solution and in the electroluminescent device. Complex 2a, [Ir(ppy)2(2,5-tpy)]PF6 was found to be an orange emitter (604 nm) both in solution and in the LEEC. LEECs incorporating both of these complexes were stable over the course of around 4–6 hours. Complex 1b, [Ir(dFMeppy)2(2,5-dpp)]PF6, was also determined to emit in the orange (605 nm) but with a photoluminescent quantum yield (ΦPL) double that of 2a. Complex 2b, [Ir(dFMeppy)2(2,5-tpy)]PF6 is an extremely bright green emitter (544 nm, 93%). All four complexes exhibited quasireversible electrochemistry and all four complexes phosphoresce from a mixed charge-transfer excited state.
AB - Four cationic iridium(III) complexes of the form [Ir(C^N)2(N^N)]+ bearing either a 2,5-dipyridylpyrazine (2,5-dpp) or a 2,2′:5′,2′′-terpyridine (2,5-tpy) ancillary ligand and either 2-phenylpyridine (ppy) or a 2-(2,4-difluorophenyl)-5-methylpyridine (dFMeppy) cyclometalating ligands were synthesized. The optoelectronic properties of all complexes have been fully characterized by UV-visible absorption, cyclic voltammetry and emission spectroscopy. The conclusions drawn from these studies have been corroborated by DFT and TDDFT calculations. The four complexes were assessed as emitters in light-emitting electrochemical cells. Complex 1a, [Ir(ppy)2(2,5-dpp)]PF6, was found to be a deep red emitter (666 nm) both in acetonitrile solution and in the electroluminescent device. Complex 2a, [Ir(ppy)2(2,5-tpy)]PF6 was found to be an orange emitter (604 nm) both in solution and in the LEEC. LEECs incorporating both of these complexes were stable over the course of around 4–6 hours. Complex 1b, [Ir(dFMeppy)2(2,5-dpp)]PF6, was also determined to emit in the orange (605 nm) but with a photoluminescent quantum yield (ΦPL) double that of 2a. Complex 2b, [Ir(dFMeppy)2(2,5-tpy)]PF6 is an extremely bright green emitter (544 nm, 93%). All four complexes exhibited quasireversible electrochemistry and all four complexes phosphoresce from a mixed charge-transfer excited state.
KW - Molecular-orbital methods
KW - Extended basis-sets
KW - Valence basis-sets
KW - Compact effective potentials
KW - Transition-metal-complexes
KW - Density-functional theory
KW - Excited-state properties
KW - Exponent basis-sets
KW - Gaussian-type basis
KW - Photophysical properties
UR - http://www.rsc.org/suppdata/dt/c4/c4dt02100b/c4dt02100b1.pdf
UR - https://www.scopus.com/pages/publications/84906317506
U2 - 10.1039/c4dt02100b
DO - 10.1039/c4dt02100b
M3 - Article
SN - 1477-9226
VL - 43
SP - 13672
EP - 13682
JO - Dalton Transactions
JF - Dalton Transactions
IS - 36
ER -