255829-32-4Relevant academic research and scientific papers
Starburst-Type Carbazole Trimers as Host Materials for Solution-Processed Phosphorescent OLEDs
Okamura, Naoki,Funagoshi, Hiroshi,Ikawa, Shigeru,Yagi, Shigeyuki,Maeda, Takeshi,Nakazumi, Hiroyuki
, p. 59 - 63 (2015)
Novel starburst-type carbazole trimers SB-1 and SB-2 were developed as hole-transporting host materials for phosphorescent organic light-emitting diodes (PhOLEDs). The triplet levels (T1s) of SB-1 and SB-2 were determined as at 2.81 and 2.73 eV
Design and synthesis of efficient electrogenerated chemiluminescent emitters derived from pyrene
Cappellari, Maria V.,Mangione, María I.,Spanevello, Rolando A.,Marzari, Gabriela,Morales, Gustavo M.,Fungo, Fernando
, p. G163 - G170 (2019/05/21)
The design and synthesis of novel dendrimeric structures derived from a pyrene core with substituted triphenylamine and carbazole periphery demonstrated how molecular engineering allowed the fine tuning of the electrogenerated chemiluminiscence (ECL) properties. These two compound (Py-CBZ and Py-TPA) in comparison with the parent structures (Py and Py-Core) showed better chemical stability and anti-aggregation capability. At the same time, the photophysical (Absλmax, E00FLλmaxΦFL), photochemical (oxygen quenching), electrochemical (redox potentials) and optoelectronic (HOMO-LUMO gap and their energy position) properties were modulated, resulting in obtaining two highly ECL emitting molecular structures (Py-CBZ and Py-TPA). This study showed that functionalization of organic dyes with redox moieties (with the proper linker and position) improved the radical stability and also, modulated the optoelectronic properties with the concomitant enhancement of the ECL performance and their potential use in applications such as organic light-emitting devices.
Easily oxidizable triarylamine materials with naphthalene and binaphthalene core: structure–properties relationship
Kerner, Luká?,Gmucová, Katarína,Ko?í?ek, Jozef,Pet?í?ek, Václav,Putala, Martin
, p. 7081 - 7092 (2016/10/14)
We devised and synthesized a series of electron-rich compounds featuring diphenylamine, carbazole or dibenzo[c,g]carbazole connected via phenylacetylene linkers to an aromatic central unit. The key synthetic step was a high yielding cross coupling reaction between halogenated (bi)naphthalene and organometallic reagents prepared in situ from terminal alkynes (side-arms). By masking one of the iodo functions with a diethyltriazenyl group in the side-arm precursors, we efficiently circumvented the formation of doubly aminated by-products. Although one step longer, this approach led to higher yields of terminal alkynes than the direct coupling route. Spectroscopic and electrochemical measurements supported by computational evidence revealed that conjugation in the 1,4-disubstituted naphthalene backbone is superior to the 1,5 or 2,6 substituted cores. The diphenylamine derivative gets oxidized more readily when compared to its carbazole analogs. Expanding the core to binaphthalene did not alter electronic properties, but influenced the physical characteristics significantly.
Evaluation of bis-cyclometalated alkynylgold(III) sensitizers for water photoreduction to hydrogen
Yu, Zhen-Tao,Liu, Xiao-Le,Yuan, Yong-Jun,Li, Yong-Hui,Chen, Guang-Hui,Zou, Zhi-Gang
supporting information, p. 17223 - 17232 (2016/11/13)
Well-defined gold sensitizers for hydrogen production from water remain extremely rare despite decades of interest, and are currently limited to systems based on ruthenium, iridium or platinum complexes. This report details the synthesis and characterization of a series of neutral cyclometalated gold(iii) complexes of the type [(RC^N^CR)Au(CC-R′)] (R = H or tert-butyl group; R′ = aryl groups) that have been found to be good candidates to function as harvesting materials in light-induced electron transfer reactions. We established the efficacy of systems with these gold(iii) complexes as photosensitizers (PSs) in the production of renewable hydrogen in the presence of [Co(2,2′-bipyridine)3]Cl2 or [Rh(4,4′-di-tert-butyl-2,2′-bipyridine)3](PF6)3 as a H2-evolved catalyst and triethanolamine (TEOA) as a sacrificial electron donor in acetone-water solution. All complexes are active, and there is a more than threefold increase over other candidates in photocatalytic H2 generation activity. Under the optimal reaction conditions, hydrogen evolution took place through a photochemical route with the highest efficiency and with a turnover number (TON) of up to 1441.5 relative to the sensitizer over 24 hours. In the initial photochemical path, the reductive quenching of the excited gold(iii) complex by TEOA due to the latter's greater concentration in the system followed by electron transfer to the catalyst species is proposed to be the dominant mechanism. A photo-to-H2 quantum yield of approximately 13.7% was attained when illuminated with monochromatic light of 400 nm. Such gold(iii) complexes have demonstrated significant utility in solar-to-hydrogen reactions and thus represent a new effective class of light-harvesting materials. These results open possibilities for pursuing more efficient photosensitizers featuring gold(iii) complexes in photocatalytic solar energy conversion.
One-pot two-step synthesis of: N -arylcarbazole-based skeleton
Tao, Sheng,Liu, Ning,Dai, Bin
, p. 43250 - 43260 (2016/05/24)
A highly site-selective, one-pot, sequential C-N and C-C bond forming process was developed, affording a carbazole-based skeleton that contains biphenyl and diarylacetylene cores. The success of this process is attributed to the use of fluorinated iodoarenes as the starting material, the fluorine group of which preferentially reacts with carbazole. The subsequent coupling of the intermediate iodinated N-arylcarbazole with arylboronic acid or arylacetylene produced the desired products. The intermediate underwent a Pd-catalyzed Ullmann coupling with excess fluorinated iodoarenes in the absence of arylboronic acid or arylacetylene, resulting in Ullmann coupling products in a one-pot process.
Synthesis and photochemical properties of 3,6-di-tert-butyl-9H-carbazole derivatives
Gruzdev,Chervonova,Venediktov,Rozhkova,Kolker,Mazaev,Dudina,Domracheva
, p. 1431 - 1439 (2015/08/03)
Method of synthesis has been developed for a series of 3,6-di-tert-butyl-9H-carbazole derivatives and their photochemical properties have been investigated. The dependence of the Steglich esterification reaction on the nature of the catalyst was studied. The synthesized compounds show fluorescent emission in the range 400-600 nm with a high quantum yield.
Copper/β-diketone-catalysed N-arylation of carbazoles
Chen, Fei,Liu, Ning,Ji, Enhui,Dai, Bin
, p. 51512 - 51523 (2015/06/25)
A copper-catalysed C-N bond-forming reaction of carbazoles with aryl iodides is described. Several commercially available ligands such as β-diketone and diamine, are tested in the N-arylation of carbazoles. The catalytic system generated in situ from an inexpensive copper salt, simple β-diketone and inorganic base efficiently N-arylated the carbazoles. A wide range of aryl iodides and carbazoles can be coupled to generate N-arylcarbazoles in the presence of various functional groups. However, the sterically hindered effect of aryl iodides is evident in this catalytic system. The selectivity of two iodine atoms on the aromatic ring of diiodobenzene is evaluated in the developed catalytic system. Results showed that the selectivity of diiodobenzene can be tuned by the reaction temperature.
Synthesis and characterization of deep blue emitters from starburst carbazole/fluorene compounds
Zhao, Zujin,Xu, Xinjun,Chen, Xiaopeng,Wang, Xiaoming,Lu, Ping,Yu, Gui,Liu, Yunqi
, p. 2658 - 2668 (2008/09/19)
A series of well-defined, highly fluorescent starburst compounds with a carbazole core and oligo(2,7-fluorene ethynylene) arms have been synthesized by Sonogashira coupling reaction and fully characterized. These conjugated compounds exhibit good solubility, high thermal stability, and excellent fluorescence quantum yields (up to 0.99). The incorporation of carbazole core interrupted the main-chain conjugation and resulted in blue-shifted absorption and emission. Moreover, deep blue light has been approached from organic light-emitting diodes (OLEDs) adopting these compounds as emitting layer.
Synthesis and crystal structures of isolable terminal aryl hexatriyne and octatetrayne derivatives: Ar-(C≡C)nH (n = 3, 4)
Wang, Changsheng,Batsanov, Andrei S.,West, Kara,Bryce, Martin R.
supporting information; experimental part, p. 3069 - 3072 (2009/04/12)
(Chemical Equation Presented) Unprecedented stability has been observed in terminal aryl hexatriyne and terminal aryl octatetrayne derivatives by judicious choice of a bulky, nonplanar headgroup [viz., 4-(3,6-di-tert-butyl-N- carbazolyl)phenyl] which hinders topochemical intermolecular interactions in the crystal lattice.
High triplet energy polymer as host for electrophosphorescence with high efficiency
Chen, Yen-Chun,Huang, Guo-Sheng,Hsiao, Chung-Chin,Chen, Show-An
, p. 8549 - 8558 (2007/10/03)
We report the conjugated polymer P(tBu-CBP) as a host with high triplet energy (ET 2.53 eV) and suitable HOMO (5.3 eV) and LUMO (2.04 eV) energy levels. Upon doping with green and red emission Ir-complexes, it gives devices with high luminous a
