57103-01-2Relevant articles and documents
Development of colloidally stable carbazole-based fluorescent nanoaggregates
Svechkarev, Denis,Kyrychenko, Alexander,Payne, William M.,Mohs, Aaron M.
, p. 55 - 64 (2018)
Fluorescent nanomaterials require high colloidal stability for effective use in imaging and sensing applications. We herein report the synthesis of carbazole-based organic fluorescent nanoaggregates, and demonstrate the superior colloidal stability of alkyl-substituted dye aggregates over their non-alkylated analogs. The role of alkyl chains in self-assembly and stability of such nanoaggregates is discussed based on both experimental and molecular dynamics simulation data, and spectral characteristics of the precursor dyes and their aggregates are described. The obtained results provide new insights on development of colloidally stable organic fluorescent nanomaterials with low polydispersity.
Enhancement of redox stability and electrochromic performance of aromatic polyamides by incorporation of (3,6-dimethoxycarbazol-9-yl)-triphenylamine units
Wang, Hui-Min,Hsiao, Sheng-Huei
, p. 272 - 286 (2014)
New series aromatic polyamides with (carbazol-9-yl)triphenylamine units were synthesized from a newly synthesized diamine monomer, 4,4′-diamino- 4″-(3,6-dimethoxycarbazol-9-yl) triphenylamine, and aromatic dicarboxylic acids via the phosphorylation polyamidation technique. These polyamides exhibit good solubility in many organic solvents and can be solution-cast into flexible and strong films with high thermal stability. They show well-defined and reversible redox couples during oxidative scanning, with a strong color change from colorless neutral form to yellowish green and blue oxidized forms at applied potentials scanning from 0.0 to 1.3 V. They show enhanced redox-stability and electrochromic performance as compared to the corresponding analogs without methoxy substituents on the active sites of the carbazole unit. Copyright
A simple strategy to achieve efficient thermally activated delayed fluorescent emitters via enhancing electron donating ability of donors
Li, Ganggang,Li, Jiafang,Li, Kai,Liu, He,Liu, Zhiwen,Wang, Zhiming,Yang, Chuluo,Zhan, Qun,Zhang, Bing,Zhou, Changjiang
, (2020/05/18)
Simultaneously achieving both effective reverse intersystem crossing (RISC) process and high values of radiative decay rate (kr)/photoluminescent quantum yield (PLQY) are critical for efficient thermally activated delayed fluorescent (TADF) emitters. The separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) through typical molecular geometry tuning method guarantees a small ΔEST but results in disfavored oscillator strength for fluorescent decay. Herein, a simple method is provided to facilitate the reverse intersystem crossing (RISC) of TADF emitters via enhancing electron donating property of donors rather than twisting the donor-acceptor configuration. Three molecules, namely Me-Cz, Me-MOC and Me-DOC, are designed and synthesized. The introduction of methoxy group enhances the electron-donating ability of carbazole. The stabilized charge transfer state features a reduced splitting energy between the first singlet and triplet excited state, thus activating TADF process. Consequently, the molecules Me-DOC and Me-MOC achieve good external quantum efficiency of 18.6% and 12.4% in electroluminescent devices.
Methoxy- and tert-butyl-substituted meta-bis(N-carbazolyl)phenylenes as hosts for organic light-emitting diodes
Keruckas, Jonas,Volyniuk, Dmytro,Simokaitiene, Jurate,Narbutaitis, Edgaras,Lazauskas, Algirdas,Lee, Pei-Hsi,Chiu, Tien-Lung,Lin, Chi-Feng,Arsenyan, Pavel,Lee, Jiun-Haw,Grazulevicius, Juozas V.
, p. 317 - 326 (2019/07/02)
Two new analogues of a popular host material, meta-bis(N-carbazolyl)phenylene (mCP), bearing either methoxy- (mCP-OMe) or tert-butyl (mCP-t-Bu) substituents at C-3 and C-6 positions of carbazole moieties were synthesized and characterized. These materials exhibit higher glass-transition temperatures (79 and 145 °C) than mCP (67 °C). They show reversibility upon electrochemical oxidation while preserving high enough triplet energy levels (2.86 and 2.97 eV). The vacuum-deposited layer of mCP-t-Bu showed hole mobility of 8 × 10?3 cm2V?1s?1 at the electric field of 1.2 × 105 Vcm?1. This value is more than by one order of magnitude higher than that of mCP. The new compounds were tested as hosts for commercial emitters: blue phosphor, bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic), green and blue thermally-activated delayed fluorescence (TADF) emitters 1,2,3,5-tetrakis(9-carbazolyl)-4,6-dicyanobenzene (4CzIPN) and bis[4-(9,9-dimethyl-9,10-dihydroacridin-10-yl)phenyl]sulfone (DMAC-DPS). Blue phosphorescent OLED based on mCP-t-Bu as the host showed up to 22.0% external quantum efficiency. When doping 4CzIPN into mCP-OMe host, a broad emission with peaks at 388, 514, and 572 nm was observed.
