Intramolecular hydrogen bond – enhanced electroluminescence performance of hybridized local and charge transfer (HLCT) excited-state blue-emissive materials

2021 ◽  
Author(s):  
Wan Li ◽  
Pongsakorn Chasing ◽  
Wachara Benchaphanthawee ◽  
Phattananawee Nalaoh ◽  
Thanyarat Chawanpunyawat ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Utilization Efficiency ◽  
High Brightness ◽  
Singlet Exciton ◽  
High Maximum ◽  
Intramolecular Hydrogen

OLED devices based on o-hydroxyphenyl phenanthroimidazole (HPI) emitters showed a high maximum external quantum effciency of 8.13% with high brightness of 18 100 cd m−2 and a maximum singlet exciton utilization efficiency of as high as 94%.

Elaborating a new excited state intramolecular proton transfer (ESPT) mechanism for a new π-conjugated dye 2, 2′-((5-(2-(4-methoxyphenyl)ethenyl)-benzene-1,1-diyl)-bis-(nitrilomethylylidene)-diphenol)

2018 ◽  
Vol 96 (3) ◽  
pp. 351-357 ◽  
Author(s):  
Dapeng Yang ◽  
Min Jia ◽  
Xiaoyan Song ◽  
Qiaoli Zhang
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Density Functional ◽  
Dynamical Behavior ◽  
Intramolecular Proton Transfer ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

In this work, the excited state dynamical behavior of a novel π-conjugated dye 2,2′-((5-(2-(4-methoxyphenyl)ethenyl)-benzene-1,1-diyl)-bis-(nitrilomethylylidene)-diphenol) (C1) has been investigated. Two intramolecular hydrogen bonds of C1 are tested to pre-existing in the ground state via AIM and reduced density gradient. Using a time-dependent density functional theory (TDDFT) method, it has been substantiated that the intramolecular hydrogen bonds of C1 should be strengthened in the S1 state via analyzing fundamental bond length, bond angles, and corresponding infrared vibrational modes. The most obvious variation of these two hydrogen bonds is the O4–H5···N6 bond, which might play important roles in excited state behavior for the C1 system. Furthermore, based on electronic excitation, charge transfer could occur. Just due to this kind of charge re-distribution, two hydrogen bonds should be tighter in the first excited state, which is consistent with the variation of hydrogen bond lengths. Thus, the phenomenon of charge transfer is reasonable evidence for confirming the occurrence of the excited state proton transfer (ESPT) process in the S1 state. Our theoretically constructed potential energy surfaces of C1 show that excited state single proton transfer should occur along with the O4–H5···N6 hydrogen bond rather than the O1–H2···N3 bond. We not only clarify the ESIPT mechanism for C1 but put forward new affiliation and explain a previous experiment successfully.

N−H-Type Excited-State Proton Transfer in Compounds Possessing a Seven-Membered-Ring Intramolecular Hydrogen Bond

2016 ◽  
Vol 22 (41) ◽  
pp. 14688-14695 ◽  
Author(s):  
Yi-An Chen ◽  
Fan-Yi Meng ◽  
Yen-Hao Hsu ◽  
Cheng-Hsien Hung ◽  
Chi-Lin Chen ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Proton Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Membered Ring ◽  
Excited State Proton Transfer ◽  
Intramolecular Hydrogen
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