86-28-2Relevant articles and documents
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.
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.
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.
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.
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.
Design, synthesis and evaluation of carbazole derivatives as potential antimicrobial agents
Xue, Yi-Jie,Li, Ming-Yue,Jin, Xue-Jun,Zheng, Chang-Ji,Piao, Hu-Ri
, p. 295 - 306 (2021/01/13)
Five series of novel carbazole derivatives containing an aminoguanidine, dihydrotriazine, thiosemicarbazide, semicarbazide or isonicotinic moiety were designed, synthesised and evaluated for their antimicrobial activities. Most of the compounds exhibited potent inhibitory activities towards different bacterial strains (including one multidrug-resistant clinical isolate) and one fungal strain with minimum inhibitory concentrations (MICs) between 0.5 and 16 μg/ml. Compounds 8f and 9d showed the most potent inhibitory activities (MICs of 0.5–2 μg/ml). Furthermore, compounds 8b, 8d, 8f, 8k, 9b and 9e with antimicrobial activities were not cytotoxic to human gastric cancer cell lines (SGC-7901 and AGS) or a normal human liver cell line (L-02). Structure–activity relationship analyses and docking studies implicated the dihydrotriazine group in increasing the antimicrobial potency and reducing the toxicity of the carbazole compounds. In vitro enzyme activity assays suggested that compound 8f binding to dihydrofolate reductase might account for the antimicrobial effect.
