Topic
Xanthene
About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.
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TL;DR: The combined analysis of emitter fluorescence quenching and acceptor fluorescence enhancement indicates that the significant bioluminescence intensity decrease in the presence of xanthene dyes is determined by both the quench processes via the energy transfer and the inhibition of biolumscent reaction.
Abstract: The paper reports the experimental results of bioluminescence quenching in the coupled enzyme system NADH:FMN-oxidoreductase-luciferase in the presence of xanthene dyes (fluorescein, eosin Y, erythrosin B) featured by the rate constants of intersystem crossing. From the spectral data and with the help of kinetic model the rate constants of energy transfer from emitter to dye were determined (2.9 × 1012–6.5 × 1013 M−1 s−1) and the emitter lifetime was estimated (1.2–2.7 ns). The calculated rate constants of energy transfer in a series of xanthene molecules are higher than the diffusion-controlled constants. The rate constants of energy transfer correlate with the probability of intersystem crossing of a dye. The combined analysis of emitter fluorescence quenching and acceptor fluorescence enhancement indicates that the significant bioluminescence intensity decrease in the presence of xanthene dyes is determined by both the quenching processes via the energy transfer and the inhibition of bioluminescent reaction.
11 citations
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TL;DR: A series of new aromatic poly(ether ester)s containing cardo xanthene groups were synthesized by phase transfer-catalyzed interfacial polycondensation of three cardo bisphenols as mentioned in this paper.
Abstract: A series of new aromatic poly(ether ester)s containing cardo xanthene groups were synthesized by phase transfer–catalyzed interfacial polycondensation of three cardo bisphenols such as 9,9-bis(4-hydroxyphenyl)xanthene, 9,9-bis (4-hydroxy-3-methylphenyl)xanthene, and 9,9-bis(4-hydroxy-3,5-dimethylphenyl)xanthene with terephthaloyl chloride and isophthaloyl chloride. Inherent viscosities and number average molecular weights of the polymers were in the range 0.56–0.80 dL g−1 and 30,300–36,200, respectively. The resulting poly(ether ester)s exhibited high glass transition temperatures ranged from 208°C to 274°C, and their 10% weight loss temperatures were in the range of 440–458°C with char yields above 45% at 600°C under a nitrogen atmosphere. All the poly(ether ester)s were amorphous and readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidinone at room temperature and could be ca...
11 citations
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TL;DR: In this article, a series of novel 9-{2]-1,2,3-triazol-4-yl)methoxy]phenyl derivatives were synthesized by a click chemistry approach.
Abstract: A series of novel 9-{2-[(1H-1,2,3-triazol-4-yl)methoxy]phenyl}-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione derivatives were synthesized by a click chemistry approach. The structures of all the newly synthesized compounds were characterized by IR, MASS, 1H and 13C NMR spectral data. The final analogues showed good to excellent antibacterial and antifungal activities in an agar well diffusion assay. Compounds 6i and 6f were the most active against all the test bacterial and fungal strains.
11 citations
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TL;DR: An efficient and environmentally benign protocol for the synthesis of dibenzo [b,i]xanthene-tetraones and fluorescent hydroxyl naphthalene-1,4-diones in the presence of a catalytic amount of ZrOCl2·8H2O as an inexpensive and eco-friendly catalyst with high catalytic activity under solvent-free conditions is reported in this paper.
Abstract: An efficient and environmentally benign protocol for the synthesis of dibenzo [b,i]xanthene-tetraones and fluorescent hydroxyl naphthalene-1,4-diones in the presence of a catalytic amount of ZrOCl2·8H2O as an inexpensive and eco-friendly catalyst with high catalytic activity under solvent-free conditions is reported.
11 citations
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TL;DR: A Bronsted acid controlled Diels-Alder reaction of 3-vinylchromones with arynes has been developed in this paper, where different kinds and amounts of acid, 9-aryl-9H-xanthen-9-ols or ortho-hydroxybenzophenones could be controllably furnished in good yields in an atom and step-economic manner.
11 citations