DC Field | Value | Language |
---|---|---|
dc.contributor.author | Hwang, Jeongwook | ko |
dc.contributor.author | Ahn, Mina | ko |
dc.contributor.author | Choi, Jungkweon | ko |
dc.contributor.author | Wee, Kyung-Ryang | ko |
dc.date.accessioned | 2021-01-28T05:57:05Z | - |
dc.date.available | 2021-01-28T05:57:05Z | - |
dc.date.created | 2020-10-19 | - |
dc.date.issued | 2020-10 | - |
dc.identifier.citation | CHEMPHYSCHEM, v.21, no.20, pp.2320 - 2326 | - |
dc.identifier.issn | 1439-4235 | - |
dc.identifier.uri | http://hdl.handle.net/10203/280087 | - |
dc.description.abstract | The inter-ligand energy transfer (ILET) process in heteroleptic iridium complex,[Ir(dfppy)(2)(bpy-Im(2))](+), where dfppy=2-(2,4-difluorophenyl)pyridine andbpy-Im(2)=4,4'-bis(1,2-diphenyl-1H-benzo[d]imidazole)-2,2',-bipyridine, was investigated using a femtosecond transient absorption (fs-TA) spectroscopic technique. The photophysical properties of [Ir(dfppy)(2)(bpy-Im(2))](+) with significantly expanding pi-conjugated ligand are compared to those of[Ir(dfppy)(2)(bpy)](+) (bpy=2,2'-bipyridine) and a free bpy-Im(2) ligand. The emission spectrum of [Ir(dfppy)(2)(bpy-Im(2))](+) shows no shift upon changing the solvent polarity, whereas the free ligand bpy-Im(2) showed bathochromic fluorescence shifts with increasing solvent polarity, which is attributed to intramolecular charge transfer (ICT). The unique photophysical properties of[Ir(dfppy)(2)(bpy-Im(2))](+) are due to the fast ILET process from (MLCTdfppy)-M-3 to (MLCT)-M-3/(LCbpy-Im2)-L-3, resulting in the phosphorescence emission originating from (MLCT)-M-3/(LCbpy-Im2)-L-3. On the other hand, the TA bands ofbpy-Im(2)are observed at 540 and 480 nm, corresponding to the singlet and triplet manifolds, respectively. In contrast, the TA spectrum of[Ir(dfppy)(2)(bpy-Im(2))](+)showes broad bands centered at 420 and 600 nm, attributed to the transitions from (MLCTdfppy)-M-3 and (MLCT)-M-3/(LCbpy-Im2)-L-3, respectively. Time-resolved spectroscopic results confirm the efficient ILET dynamics from (MLCTdfppy)-M-3 to (MLCT)-M-3/(LCbpy-Im2)-L-3 in [Ir(dfppy)(2)(bpy-Im(2))](+). From the relaxation times determined by singular value decomposition analysis and simple sequential kinetic model, we infer that the ILET process from (MLCTdfppy)-M-3 to (MLCT)-M-3/(LCbpy-Im2)-L-3 occurs with a time constant of ca. 4 ps. The presented results in this study show that the introduction of an expanding pi-conjugated ligand can lead to the efficient ILET dynamics for improving the OLED performance. | - |
dc.language | English | - |
dc.publisher | WILEY-V C H VERLAG GMBH | - |
dc.title | Inter-Ligand Energy Transfer Process in an Ir-Complex with Expanding pi-Conjugated Ligand | - |
dc.type | Article | - |
dc.identifier.wosid | 000573577600001 | - |
dc.identifier.scopusid | 2-s2.0-85091731666 | - |
dc.type.rims | ART | - |
dc.citation.volume | 21 | - |
dc.citation.issue | 20 | - |
dc.citation.beginningpage | 2320 | - |
dc.citation.endingpage | 2326 | - |
dc.citation.publicationname | CHEMPHYSCHEM | - |
dc.identifier.doi | 10.1002/cphc.202000565 | - |
dc.contributor.nonIdAuthor | Hwang, Jeongwook | - |
dc.contributor.nonIdAuthor | Ahn, Mina | - |
dc.contributor.nonIdAuthor | Wee, Kyung-Ryang | - |
dc.description.isOpenAccess | N | - |
dc.type.journalArticle | Article | - |
dc.subject.keywordAuthor | inter-ligand energy transfer | - |
dc.subject.keywordAuthor | iridium complex | - |
dc.subject.keywordAuthor | pi-expanding effect | - |
dc.subject.keywordAuthor | phosphorescence | - |
dc.subject.keywordAuthor | species-associated spectra | - |
dc.subject.keywordPlus | HETEROLEPTIC IRIDIUM(III) COMPLEXES | - |
dc.subject.keywordPlus | CYCLOMETALATED IR(III) COMPLEXES | - |
dc.subject.keywordPlus | SINGULAR-VALUE DECOMPOSITION | - |
dc.subject.keywordPlus | ANCILLARY LIGANDS | - |
dc.subject.keywordPlus | EMISSION | - |
dc.subject.keywordPlus | STATE | - |
dc.subject.keywordPlus | PHOSPHORESCENCE | - |
dc.subject.keywordPlus | EFFICIENCY | - |
dc.subject.keywordPlus | DYNAMICS | - |
dc.subject.keywordPlus | BLUE | - |
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