Synthesis and Properties of Carbazole Main Chain Copolymers with Oxadiazole Pendant toward Bipolar Polymer Host: Tuning the HOMO/LUMO Level and Triplet Energy

2008 ◽  
Vol 20 (23) ◽  
pp. 7324-7331 ◽  
Author(s):  
Kai Zhang ◽  
Youtian Tao ◽  
Chuluo Yang ◽  
Han You ◽  
Yang Zou ◽  
...  
Keyword(s):  
Main Chain ◽  
Triplet Energy ◽  
Lumo Level ◽  
Homo Lumo ◽  
Polymer Host

Synthesis and characterization of red light-emitting electrophosphorescent polymers with different triplet energy main chain

Polymer ◽  
2011 ◽  
Vol 52 (10) ◽  
pp. 2189-2197 ◽  
Author(s):  
Zhihua Ma ◽  
Junqiao Ding ◽  
Yanxiang Cheng ◽  
Zhiyuan Xie ◽  
Lixiang Wang ◽  
...  
Keyword(s):  
Main Chain ◽  
Red Light ◽  
Synthesis And Characterization ◽  
Triplet Energy ◽  
Light Emitting

Saturated N,X-Heterocyclic Carbenes (X=N, O, S, P, Si, C, and B): Stability, Nucleophilicity, and Basicity

2015 ◽  
Vol 68 (9) ◽  
pp. 1438 ◽  
Author(s):  
Zahra Azizi ◽  
Mehdi Ghambarian ◽  
Mohammad A. Rezaei ◽  
Mohammad Ghashghaee
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Energy Difference ◽  
Heterocyclic Carbenes ◽  
Structure Stability ◽  
Triplet Energy ◽  
Lumo Energy ◽  
Dft Methods ◽  
Functional Theory ◽  
Homo Lumo

Various saturated five-membered N,X-heterocyclic carbenes (X = N, O, S, P, Si, C, and B) have been studied by ab initio and density functional theory (DFT) methods. The substitutions alter the properties of the reference carbene from the viewpoint of electronic structure, stability, nucleophilicity, and basicity. Our study shows that the oxygen containing carbene (X = O) induces the highest HOMO–LUMO energy gap (ΔEHOMO–LUMO), while carbene with X = N has the widest singlet–triplet energy difference (ΔEs–t). The nucleophilicity of the carbene derivatives increased upon replacement of C, Si, and B, with the effect of the boron substituent being more pronounced. In addition, the basicity of the structure increased for the carbene derivatives with X = C and B with the latter substitution imposing a remarkably higher effect. Moreover, the substitution of boron at the α-position of the carbene increased the nucleophilicity and basicity, while inducing a reduction in the values of ΔEs–t and ΔEHOMO–LUMO.

Poly(m-phenylene): Conjugated Polymer Host with High Triplet Energy for Efficient Blue Electrophosphorescence

2010 ◽  
Vol 43 (23) ◽  
pp. 9608-9612 ◽  
Author(s):  
Jun Liu ◽  
Qibing Pei
Keyword(s):  
Conjugated Polymer ◽  
Triplet Energy ◽  
Polymer Host

Bis(2-(benzo[d]thiazol-2-yl)-5-fluorophenolate)beryllium: a high-performance electron transport material for phosphorescent organic light-emitting devices

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 5008-5015 ◽  
Author(s):  
Dong Chen ◽  
Liang Han ◽  
Weiping Chen ◽  
Zhenyu Zhang ◽  
Shitong Zhang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Mobility ◽  
High Performance ◽  
High Electron ◽  
Triplet Energy ◽  
High Electron Mobility ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Lumo Level

A beryllium complex with a low-lying LUMO level, high triplet energy and high electron mobility served as an excellent electron transport material for green, yellow and red phosphorescent OLEDs.

scholarly journals Evaluation of the Effect of π Conjugate Plane Distortion on the HOMO-LUMO Level of Nanographene by Photoemission Yield Spectroscopy in Air

2018 ◽  
Vol 67 (11) ◽  
pp. 693-697
Author(s):  
Yasuto FUJIMAKI ◽  
Keisuke OGUMI ◽  
Kosei HAYASHI ◽  
Hiroto WATANABE
Keyword(s):  
Lumo Level ◽  
Homo Lumo

Synthesis and characterization of high triplet energy polyfluorene bearing m-tetraphenylsilane segment as a polymer host for green phosphorescent polymer light emitting diodes

2015 ◽  
Vol 204 ◽  
pp. 70-75 ◽  
Author(s):  
Qinghua Zhao ◽  
Wanyun Zhang ◽  
Zhuxin Fan ◽  
Jinjin Li ◽  
Xiaomin Chen ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Synthesis And Characterization ◽  
Triplet Energy ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes ◽  
Polymer Host

Fluorinated Poly(N-vinylcarbazole) Host for Triplet Energy Confinement on Phosphorescent Emitter in Organic Light-emitting Diodes

2009 ◽  
Vol 1197 ◽  
Author(s):  
Yukitami Mizuno ◽  
Isao Takasu ◽  
Shuichi Uchikoga ◽  
Shintaro Enomoto ◽  
Tomoaki Sawabe ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Energy Gap ◽  
Organic Light Emitting Diodes ◽  
Lumo Energy ◽  
Light Emitting ◽  
Energy Gaps ◽  
Organic Light ◽  
Host Materials ◽  
Homo Lumo ◽  
Polymer Host

AbstractFluorinated carbazoles as host materials have been investigated for highly efficient organic light emitting diodes (OLEDs). By molecular orbital calculations, we found that fluorinations at position 2, 4, 5 and 7 of carbazole ring were effective for widening HOMO-LUMO energy gap. The energy gaps of our synthesized 2,7-difluorocarbazole (F2-Cz) and 2,4,5,7-tetrafluorocarbazole (F4-Cz), were estimated to be 3.71 eV and 3.87 eV by the absorption spectra, respectively. These energy gaps were higher than that of the non-substituted carbazole (Cz, 3.59 eV). We synthesized poly(N-vinyl-2,7-difluorocarbazole) (F2-PVK) and poly(N-vinyl-2,4,5,7-tetrafluorocarbazole) (F4-PVK) as solution processable polymer host materials. However, the F4-PVK was found to be an unsolved polymer. The F2-PVK could be compared with non substituted poly(N-vinylcarbazole) (PVK) in OLEDs. The emission layer (EML) contained iridium(III) bis [(4,6-di-fluorophenyl)-pyridinato-N,C2′] picolinate (FIrpic) as a blue phosphorescent dopant, and iridium(III) bis [2-(9,9-dihexylfluorenyl)-1-pyridine] acetylacetonate as a yellow dopant. The white OLED with the F2-PVK showed 1.4 times higher luminous current efficiency (24 cd/A) than the PVK (17 cd/A). These data show that the excitation energy is confined on dopants by using fluorinated polymer host material with higher T1 corresponding to wider HOMO-LUMO energy gap.

Synthesis and device performance of an oxygen-interrupted bipolar polymer host with carbazole and triphenylphosphine oxide in the main chain

2016 ◽  
Vol 134 (7) ◽  
Author(s):  
Zhu-Xin Fan ◽  
Yu Bai ◽  
Zhi-Wei Chu ◽  
Xin-Wen Zhang ◽  
Qing-Hua Zhao
Keyword(s):  
Main Chain ◽  
Triphenylphosphine Oxide ◽  
Device Performance ◽  
Polymer Host

Indenofluorene congeners: Biradicaloids and beyond

2014 ◽  
Vol 86 (4) ◽  
pp. 517-528 ◽  
Author(s):  
Akihiro Shimizu ◽  
Shunpei Nobusue ◽  
Hirokazu Miyoshi ◽  
Yoshito Tobe
Keyword(s):  
Physical Properties ◽  
Ground State ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Triplet Energy ◽  
Lumo Energy ◽  
Energy Gaps ◽  
Electronic Configurations ◽  
Homo Lumo

Abstract Singlet biradicaloids are certainly one of the most frequently discussed topics at ISNA-15. In this review our own work on the synthesis, molecular structures, and physical properties relevant to biradical character of indenofluorene isomers are described. These include indeno[2,1-a]fluorene with an o-quinodimethane substructure, benz[c]indeno[2,1-a]fluorene which is the first 2,3-naphthoquinodimethane derivative isolated, and indeno[2,1-b]fluorene with an m-quinodimethane (m-xylylene) subunit. The observed physical properties are explained in terms of the theoretically derived biradical factors (y), HOMO-LUMO energy gaps, and singlet-triplet energy gaps in the ground state electronic configurations. In addition, we discuss here two perspectives in the biradicaloid chemistry, (i) two- and three-dimensional indenofluorene congeners arranged in a macrocyclic form and (ii) macrocyclic indenofluorenes having multiple radical characters.

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