1. DFT and TD-DFT Study on the Electronic Structuresand Phosphorescent Properties of a Series of Heteroleptic Iridium(III)Complexes.
- Author
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Shang, Xiaohong, Han, Deming, Zhan, Qing, Zhang, Gang, and Li, Dongfeng
- Subjects
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IRIDIUM compounds , *HETEROLEPTIC compounds , *DENSITY functional theory , *TIME-dependent density functional theory , *ELECTRONIC structure , *PHOSPHORESCENCE - Abstract
Theelectronic structures and phosphorescent properties of a seriesof heteroleptic iridium(III) complexes (mpmi)2Ir(dmpypz)(1; mpmi = 1-(4-tolyl)-3-methylimidazolium, dmpypz =3,5-dimethyl-2-(pyrazol-3-yl)pyridine), (bpmi)2Ir(dmpypz)(2; bpmi = 1-biphenyl-4-yl-3-methylimidazole), (dfmi)2Ir(dmpypz) (3; dfmi = 1-(2,6-difluorobiphenyl)-3-methylimidazole),(mtmi)2Ir(dmpypz) (4; mtmi = 1-methyl-3-(4′-(trifluoromethyl)biphenyl-4-yl)imidazole),(fmmi)2Ir(dmpypz) (5; fmmi = 1-(fluoren-2-yl)-3-methylimidazole),and (mhmi)2Ir(dmpypz) (6; mhmi = 1-methyl-3-phenanthren-2-ylimidazole)have been investigated by using density functional theory (DFT) andtime-dependent density functional theory (TDDFT) methods. The influenceof different substituent groups and π-conjugation degrees onthe optical and electronic properties of Ir(III) complexes was alsoexplored by introducing phenyl, fluorophenyl, (trifluoromethyl)phenyl,and rigid construction on the phenylimidazole moiety of a cyclometalatedligand (C∧C) in complex 1. The calculatedresults show that the lowest energy absorption wavelengths of complexes 1–6are 387, 380, 378, 375, 391, and 384nm, respectively. The introduction of different substituent groupsleads to different degrees of red shift for complexes 2–6in emission spectra in comparison with thatof complex 1. It is believed that the highest tripletmetal to ligand charge transfer 3MLCT (%) contribution,smallest ΔES1–T1and higher μS1values,and larger 3MC–3MLCT energy gap for 3ensure its higher quantum yield in comparison with thatof other complexes. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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