TY - JOUR
T1 - Iridium(III) Complexes Bearing a Formal Tetradentate Coordination Chelate
T2 - Structural Properties and Phosphorescence Fine-Tuned by Ancillaries
AU - Yuan, Yi
AU - Gnanasekaran, Premkumar
AU - Chen, Yu-Wen
AU - Lee, Gene-Hsiang
AU - Ni, Shao-Fei
AU - Lee, Chun-Sing
AU - Chi, Yun
PY - 2020/1/6
Y1 - 2020/1/6
N2 - Synthesis of the multidentate coordinated chelate N3C-H2, composed of a linked functional pyridyl pyrazole fragment plus a peripheral phenyl and pyridyl unit, was obtained using a multistep protocol. Preparation of Ir(III) metal complexes bearing a N3C chelate in the tridentate (κ3), tetradentate (κ4), and pentadentate (κ5) modes was executed en route from two nonemissive dimer intermediates [Ir(κ3-N3CH)Cl2]2 (1) and [Ir(κ4-N3C)Cl]2 (2). Next, a series of mononuclear Ir(III) complexes with the formulas [Ir(κ4-N3C)Cl(py)] (3), [Ir(κ4-N3C)Cl(dmap)] (4), [Ir(κ4-N3C)Cl(mpzH)] (5), and [Ir(κ4-N3C)Cl(dmpzH)] (6), as well as diiridium complexes [Ir2(κ5-N3C)(mpz)2(CO)(H)2] (7) and [Ir2(κ5-N3C)(dmpz)2(CO)(H)2] (8), were obtained upon treatment of dimer 2 with pyridine (py), 4-dimethylaminopyridine (dmap), 4-methylpyrazole (mpzH), and 3,5-dimethylpyrazole (dmpzH), respectively. These Ir(III) metal complexes were identified using spectroscopic methods and by X-ray crystallographic analysis of representative derivatives 3, 5, and 7. Their photophysical and electrochemical properties were investigated and confirmed by the theoretical simulations. Notably, green-emitting organic light-emitting diode (OLED) on the basis of Ir(III) complex 7 gives a maximum external quantum efficiency up to 25.1%. This result sheds light on the enormous potential of this tetradentate coordinated chelate in the development of highly efficient iridium complexes for OLED applications.
AB - Synthesis of the multidentate coordinated chelate N3C-H2, composed of a linked functional pyridyl pyrazole fragment plus a peripheral phenyl and pyridyl unit, was obtained using a multistep protocol. Preparation of Ir(III) metal complexes bearing a N3C chelate in the tridentate (κ3), tetradentate (κ4), and pentadentate (κ5) modes was executed en route from two nonemissive dimer intermediates [Ir(κ3-N3CH)Cl2]2 (1) and [Ir(κ4-N3C)Cl]2 (2). Next, a series of mononuclear Ir(III) complexes with the formulas [Ir(κ4-N3C)Cl(py)] (3), [Ir(κ4-N3C)Cl(dmap)] (4), [Ir(κ4-N3C)Cl(mpzH)] (5), and [Ir(κ4-N3C)Cl(dmpzH)] (6), as well as diiridium complexes [Ir2(κ5-N3C)(mpz)2(CO)(H)2] (7) and [Ir2(κ5-N3C)(dmpz)2(CO)(H)2] (8), were obtained upon treatment of dimer 2 with pyridine (py), 4-dimethylaminopyridine (dmap), 4-methylpyrazole (mpzH), and 3,5-dimethylpyrazole (dmpzH), respectively. These Ir(III) metal complexes were identified using spectroscopic methods and by X-ray crystallographic analysis of representative derivatives 3, 5, and 7. Their photophysical and electrochemical properties were investigated and confirmed by the theoretical simulations. Notably, green-emitting organic light-emitting diode (OLED) on the basis of Ir(III) complex 7 gives a maximum external quantum efficiency up to 25.1%. This result sheds light on the enormous potential of this tetradentate coordinated chelate in the development of highly efficient iridium complexes for OLED applications.
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U2 - 10.1021/acs.inorgchem.9b02799
DO - 10.1021/acs.inorgchem.9b02799
M3 - RGC 21 - Publication in refereed journal
SN - 0020-1669
VL - 59
SP - 523
EP - 532
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 1
ER -