86-28-2Relevant academic research and scientific papers
Push-pull fluorophores with viscosity dependent and aggregation induced emissions insensitive to polarity
Telore, Rahul D.,Satam, Manjaree A.,Sekar, Nagaiyan
, p. 359 - 367 (2015)
Abstract A series of push-pull chromophoric extended styryls from 5,5′-(9-ethyl-9H-carbazole-3,6-diyl)bis(2-morpholinothiazole-4-carbaldehyde) were synthesized by Knoevenagal condensation reaction with active methylene compounds. The intermediate carbaldehyde was synthesized from carbazole through multistep reactions. The intramolecular charge transfer of synthesized highly conjugated symmetrical D-π-A (D-donor, A-acceptor) extended styryls with rigid structure have been investigated by means of photophysical properties. The photophysical properties like absorption, emission and quantum yield of styryl derivatives were evaluated in various solvents of different polarities. All these synthesized extended styryls have exhibited aggregation induced emission with enhanced fluorescence intensity. This series of compounds can also be used as fluorescence molecular rotors for viscosity sensing. The sensitivity of viscosity towards UV absorption as well as fluorescence emission has also been investigated.
Initiation and propagation rate constants for the cationic polymerization of N-vinylcarbazole
Schimmel, Holger,Ofial, Armin R.,Mayr, Herbert
, p. 5454 - 5458 (2002)
Initiation and propagation rate constants for the cationic polymerization of N-vinylcarbazole were discussed. Benzhydryl cations were used as reference electrophiles to determine the reactivity parameters. All reactions were undertaken under dry, oxygenfr
Fluorescence Quenching Mechanism of Aromatic Hydrocarbons by Closed-Shell Heavy Metal Ions in Aqueous and Organic Solutions
Masuhara, Hiroshi,Shioyama, Hiroshi,Saito, Tokashi,Hamada, Kei,Yasoshima, Seikichi,Mataga, Noboru
, p. 5868 - 5873 (1984)
Fluorescence quenching rate constants of some aromatic hydrocarbons by Zn2+, Ag+, Cd2+, In3+, Sn2+, Cs+, Hg2+, Tl+, and Pb2+ were determined in aqueous and N,N-dimethylformamide solutions.Paramagnetic interactions, the heavy atom effect, and electron transfer were excluded as a possible quenching mechanism.N2 gas laser photolysis studies revealed that a cation radical of the fluorescer was detected only N-ethylcarbazole quenched by Ag+, Pb2+, and Hg2+ in N,N-dimethylformamide and for 1-pyrenesulfonic acid by Hg2+ in water.All other systems yielded the triplet state of the fluorescer quantitatively.The intermediates observed in the microsecond time region are the transient species with the lowest free energy.Picosecond laser photolysis of the Ag+ and Pb2+ quencher systems in N,N-dimethylformamide confirmed directly that the triplet state is induced by fluorescence quenching.On the basis of these results, it has been concluded that fluorescence quenching is due to nonfluorescent complex formation followed by rapid intersystem crossing.The electronic and geometrical structures of this complex were considered and compared to the excited aromatic hydrocarbon-halogen anion systems.
Dehydrogenation of dodecahydro-N-ethylcarbazole on Pt(111)
Gleichweit, Christoph,Amende, Max,Schernich, Stefan,Zhao, Wei,Lorenz, Michael P. A.,Hoefert, Oliver,Brueckner, Nicole,Wasserscheid, Peter,Libuda, Joerg,Steinrueck, Hans-Peter,Papp, Christian
, p. 974 - 977 (2013)
Sloshing hydrogen: Liquid organic hydrogen carriers are high-boiling organic molecules, which can be reversibly hydrogenated and dehydrogenated in catalytic processes and are, therefore, a promising chemical hydrogen storage material. One of the promising candidates is the pair N-ethylcarbazole/perhydro- N-ethylcarbazole (NEC/H12-NEC). The dehydrogenation and possible side reactions on a Pt(111) surface are evaluated in unprecedented detail. Copyright
Fabrication of Eu(III) complex doped nanofibrous membranes and their oxygen-sensing properties
Songzhu, Lin,Xiangting, Dong,Jinxian, Wang,Guixia, Liu,Wenshen, Yu,Ruokun, Jia
, p. 885 - 889 (2010)
In this paper, we report the synthesis, characterization, and photophysical properties of Eu(TTA)3ECIP, where TTA = 2-thenoyltrifluoroacetonate, and ECIP = 1-ethyl-2-(N-ethyl-carbazole-yl-4-)imidazo[4,5-f]1,10- phenanthroline. Its elementary application for oxygen-sensing application is also investigated by doping it into a polymer matrix of polystyrene (PS). Experimental data suggest that the 2.5 wt% doped Eu(TTA)3ECIP/PS nanofibrous membrane exhibits a high sensitivity of 3.4 towards oxygen with a good linear relationship of R2 = 0.9962. In addition, the 2.5 wt% doped Eu(TTA)3ECIP/PS nanofibrous membrane owns a quick response of 8 s towards oxygen, along with its excellent atmosphere insensitivity and photobleaching resistance. All these results suggest that both Eu(TTA) 3ECIP and Eu(TTA)3ECIP/PS system are promising candidates for oxygen-sensing optical sensors.
5-(N-Ethylcarbazol-3-yl)thiophene-2-carbaldehyde (ECTC): A novel fluorescent sensor for ferric ion
Zhang, Qiang,Wei, Huaixin,Zhai, Rongjia,Ji, Zhongling,Qi, Yu,Zhao, Xin
, p. 287 - 290 (2016)
5-(N-Ethylcarbazol-3-yl)thiophene-2-carbaldehyde (ECTC), was synthesized by Suzuki coupling reaction and characterized by 1H NMR, 13C NMR and elemental analysis. This compound strongly quenches fluorescence of Fe3+ ion, whereas almost no quenching is observed in the presence of other metal ions including Na+, K+, Mg2+, Ca2+, Cu2+, Mn2+ and Co2+. Under optimized conditions, the fluorescence intensity of ECTC is quenched in a linear fashion by Fe3+ ion in a wide range of 0.1 μm-10 μm with the limit of detection below 0.1 μm.
NLOphoric 3,6-di(substituted quinoxalin) Carbazoles – Synthesis, Photophysical Properties and DFT Studies
Telore, Rahul D.,Jadhav, Amol G.,Sekar, Nagaiyan
, p. 1531 - 1540 (2017)
Synthesis of novel 3,6-di(substituted quinoxalin) carbazole fluorophores by the condensation of 1,1′-(9-ethyl-9H-carbazole-3,6-diyl)bis(2-bromoethanone) with methyl, chloro and unsubstituted o-phenylenediamine is presented. Synthesized derivatives are well characterized by 1H NMR, 13C NMR, FTIR and Mass spectroscopy. Photophysical studies are carried out using solvents of varying polarities revealed positive solvatochromism and intramolecular charge transfer from carbazole (Donor) to quinoxalin (Acceptor). Intramolecular charge transfer properties are correlated by dipole moment changes and different polarity functions like Lippert–Mataga, Bilot-Kawski, Bakhshiev and Liptay plots with very good regression factors. Mulliken hush-analysis further support charge transfer characteristic. Linear and Nonlinear optical properties are explained by solvatochromic data using two-level quantum mechanical model and are correlated with computational calculations using density functional theory at B3LYP/6-31G(d) level. First hyperpolarizability value of all the synthesized compounds is found to be greater than urea by >333 times. Moreover, increase of hyperpolarizability values from non-polar to polar solvents are in good correlation with the significant charge transfer characteristic in polar solvents.
The synthesis of a series of fluorescent emitters and their application for dye lasing and cation sensing
Cang, Sheng,Liu, Liang,Tian, Yaqiang,Yang, Zixuan,Zhang, Leiyu
, (2021)
The following paper reported four carbazole-modified fluorescent emitters. Their molecular structure and electronic transition were analyzed via their single crystal and theoretical calculation. Their photophysical parameters, including absorption, emission and quantum yield, were determined and discussed. It was found that the emission performance of benzo-thiazole-based dyes was better than that of benzo-imidazole-based dyes, owing to the electron-donating effect from the S atom. Upon the presence of metal cations, these photophysical parameters were re-measured. Benzo-thiazole-based dyes were found insensitive towards most metal cations, while benzo-imidazole-based dyes showed obvious photophysical variation upon these metal cations, including absorption red shift and emission quenching. Detailed sensing performance of a representative dye was discussed. A linear working curve with good selectivity was finally observed. Its sensing mechanism was confirmed as the coordination between metal cation and deprotonated benzo-imidazole group. Benzo-thiazole-based dyes showed amplified spontaneous emission (ASE) behavior, with threshold energy of ~220 μJ. Given the optimal condition, a highest ASE efficiency of ~2% was observed, with FWHM value of 6 nm and emission peak of 435 nm. The major novelty and advancement of these fluorescent dyes shall be the stable ASE output (dye 4) under UV excitation and the linear sensing curve with good selectivity (dye 3), which was a hard task for emission turn off sensing probes. We attributed its causation to the valent-recognizing sensing mechanism.
Coumarin-carbazole based functionalized pyrazolines: Synthesis, characterization, anticancer investigation and molecular docking
Chauhan, Alex,Jain, Neeraj,Pandey, Nilesh,Parikh, Paranjay,Patel, Kaushal,Patel, Mrugesh,Timaniya, Jignesh
, p. 27627 - 27644 (2021/08/25)
A series of novel pyrazoline scaffolds from coumarin-carbazole chalcones were synthesized. We explored various acetyl, amide, and phenyl substituents at the N-1 position of the pyrazoline core. The synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR, DEPT, and mass spectroscopic techniques. The in vitro cytotoxicity study of all the synthesized compounds was evaluated against HeLa, NCI-H520 and NRK-52E cell lines. Compounds 4a and 7b became the most active compounds and exhibited their potential to arrest the cell cycle progression and induce apoptosis in both the cell lines. In addition, molecular docking studies revealed a higher binding affinity of both the molecules with CDK2 protein. Based on the obtained results, a comprehensive analysis is warranted to establish the role of compounds 4a and 7b as promising cancer therapeutic agents.
Carbazole-based π-conjugated 2,2′-Bipyridines, a new class of organic chromophores: Photophysical, ultrafast nonlinear optical and computational studies
Bodapati, Ramakrishna,Das, Samar K.,Dey, Gaurav Ranjan,Jose, K. V. Jovan,Krishnakanth, Katturi Naga,Ramteke, Gunjan R.,Rao, S. Venugopal
, (2020/11/03)
The developmen of donor-acceptor (D-A) architecture based organic chromophores with large two-photon absorption (2 PA) cross-sections are essential for myriad of applications, ranging from nonlinear microscopy to biomedical imaging. Here, we present the results from a comprehensive study of 2 PA cross-sections of a new series of carbazole mono substituted-π-conjugated-2,2′-bipyridine derivatives with D-π-A architecture, possessing carbazole as the donor moiety and bipyridine core as an acceptor. Further, we have extended the π-conjugation by introducing the phenyl and butoxy substituted phenyl linkers. The fluorescence properties of these D-A chromophores are highly sensitive to solvent polarity and alteration of electron donor functionalities. The relevant computation studies support our experimental results, e.g., a shift in emission maxima and band gaps of the molecules. The third-order nonlinear optical (NLO) properties of the title donor-acceptor (D-A) chromophores demonstrated that 2 PA cross-section values are in the range of 6–39 GM, obtained using ~50 fs (fs) laser pulses at a wavelength of 800 nm. Further, the nonlinear refractive indices (n2) of these chromophores were found to be ~10?14 cm2/W, rendering them potential optical switching candidates since the coefficients were obtained with kHz, fs pulses extracting pure electronic nonlinearities. Based on our experimental findings and theoretical calculations presented in this study, we believe that carbazole-based π-conjugated 2,2′-bipyridines, demonstrated in this work, would be potential ligands to obtain a series of transition metal coordination complexes of interesting physical properties (for example, superior NLO behaviour).
