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Showing 1 to 20 of 23 for “"Xanthene"”.
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MODIFICATION OF XANTHENE AND SILICON ANALOGUES OF XANTHENE FLUOROPHORES FOR CHEMICAL PROBES DEVELOPMENT
… probes based on rhodamines. We have modified the xanthene core of fluorescein by replacing the xanthene oxygen with a dimethylsilyl group which shows 90 nm red-shift relative to fluorescein (λabs/λem =582 nm/598 nm). These fluorophores have advantages over their oxygen counterparts because …
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XANTHENE AND SILICON ANALOGS OF XANTHENE FLUOROPHORES AS CHEMICAL SENSORS FOR pH AND HYPOCHLOROUS ACID
Chemical sensors capable of detecting a specific atom or molecule under various conditions have been utilized in biological and environmental analyses. Fluorescence based sensors are particularly advantageous in these studies because of their high sensitivity, relative ease in handling, and low …
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Exploring the potential of xanthene derivatives as inhibitors of trypanothione reductase and resistance reversal agents
Includes bibliographical references.
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Xanthene/Benzoxanthene Dyes: Novel Synthetic Metholologies, Applications in Molecular Recognition, Cellular Imaging and the Design of a Tunable White (RGB) Light Emitter
… I have developed a unique synthesis of xanthene dyes. It involves the initial formation of methylated carbinol intermediates, followed by demethylation and concomitant condensation. I successfully applied the methodology to the synthesis of hitherto unavailable type [a] and [b] …
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Immunosensors developed on clathrate platform compounds
… = 400 nm flourene derivative and λmax = 337 nm xanthene derivative ) and fluorescent (440nm and 467nm flourene derivative and 344 and 380 xanthene derivative). These compounds were drop coated onto commercial glassy carbon electrode (GCE) to produce thin films. Scan rate dependent cyclic …
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Design and Use of Fluorescent Assays to Study Plasminogen Activator and Other Serine Proteases Involved in Biological Control
… assays need to be devised. Because the xanthene dyes rhodamine and fluorescein are among the most fluorescent compounds known and, as such, can be detected at very low concentrations, derivatives of these fluorescent dyes were designed as fluorogenic substrates for the amidase and …
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Towards new model systems for the study of proton-coupled electron transfer
… to the PT event was accomplished by appending xanthene "Hangman" scaffolds to the 4' position of the tpy. The feasibility of modifying the xanthene scaffold to accommodate various hanging groups has been demonstrated. The second model system is based on Re'(CO)3(phen)(pyr) (phen = …
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Isolation and Characterization of Bioactive Metabolites from Endophytic Fungi of Pinus Strobus
… four dihydrobenzofurans derivatives (5-8), one xanthene derivative (9), and one polyoxygenated cyclohexene (10). Two of the dihydrobenzofurans compounds are new (7 and 8), while the other two (5 and 6) are reported here for the first time as natural products. Compound 4 is known as a starting …
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Photoluminescent energy transfer from poly(phenyleneethylene)s to a series of dyes
… derivative were used as the energy donor, and xanthene, cyanine, phenoxazine, and squaraine dyes were utilized as energy acceptors. Energy transfer efficiency was investigated by exciting the polymer and monitoring the quenching of polymer emission, along with the enhanced dye emission. …
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Distal hydrogen-bonding effects and cofacial bimetallic salen architectures for oxygen activation chemistry
… platforms linked cofacially by rigid pillars xanthene or dibenzofuran. A series of bimetallic complexes, including chromium, iron, manganese, cobalt, copper, and zinc were generated. Mossbauer spectroscopy was used in the characterization of the iron salen complexes, which were also examined …
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Small-molecule activation chemistry catalyzed by proton-coupled electron transfer
… two redox sites linked face-to-face by a rigid xanthene (DPX) or dibenzofuran (DPD) spacer - Pacman porphyrins. A comparative structural study demonstrates that DPD has the unprecedented ability to open and close its binding pocket by a vertical distance of over 4 A upon substrate binding, …
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X-ray crystallography for the study of nickel and iron salicylaldimines
… with J=+11.386 and J23=-13.891. Lastly, xanthene spirolactam derivatives were structurally analyzed to determine binding modes for their selective and sensitive (µM) detection of metals Cr³⁺, Fe³⁺, Ni²⁺, Co²⁺ and the nerve gas mimic, dichlorophosphate"--Abstract, page iii.</p>
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NATURAL POLYPHENOLS AS LEAD COMPOUNDS IN THE SYNTHESIS OF ANTITUMOR AGENTS AND OTHER USEFUL PRODUCTS
… the synthesis of nitrogenated lignans with a benxanthene core, whereas stilbenolignans were also obtained with laccase-mediated reactions. During this work, an unexpected enzymatic reaction afforded an hydantoin-related product and this result is also reported herein. The results of this research …
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Computer-Guided Design of Photocatalyst for PET-RAFT Polymerisation
… studies on a library of halogenated xanthene dyes. Finally, by implementing the most cutting-edged quantum chemical software packages, the fully computer-guided strategy of functional PC design for PET-RAFT polymerisation was enabled based on broadened structure-property-performance …
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Detection of Biologically Important Molecules
… the condensation of resultant products to afford xanthene dyes. This discovery has influenced the development of other indicator molecules discussed in the previous chapters. In the last chapter, I reported the synthesis of a cysteine-conjugated rhodamine dye and its application in the selective …
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Activity-based sensors for reactive aldehydes and their corresponding enzymatic machinery
… Towards this goal, eleven possible Si-xanthene probes were synthesized. Each iteration provided new insights into the electronic and steric requirements for isoform selectivity and fluorescence turn on. In the end, the careful incorporation of two fluorine atoms on the reactive …
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Development and application of palladium-catalyzed carbon-nitrogen bond forming reactions
… a Pd/9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xantphos) catalyst the desired hydrazones are produced in excellent yields and at 0.1 mol % of catalyst. The N-aryl benzophenone hydrazones are converted to indole products via an in situ hydrolysis/Fischer cyclization protocol. A …
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Permanganate oxidations of aromatic hydrocarbons in aqueous and organic solution
… fluorene, 9,10-dihydroanthracene, and xanthene. The kinetics, which were monitored by UV/vis spectroscopy, show that the reactions, regardless of solvent, are first order with respect to both permanganate and substrate concentration, with no apparent induction periods. Despite these …
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Modeling polymerization-based amplification
Eosin, a photoreducible xanthene derivative, acts as a Type II photoinitiator of free radical polymerizations when used in combination with alcohols or amines as co-initiators. Previous work utilizing eosin in polymerizations focused on high concentrations of initiators but it has recently been …
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Amphiphile Phosphane für die Anwendung in neuen polaren Medien
… bidentate phosphine ligands containing a rigid xanthene backbone and resonance stabilized cationic groups. The diprimary phosphine L21 has been obtained by dilithiation of 9,9-dimethylxanthene in 4,5-position and reaction of the dilithiated product with ClP(NEt2)2 to 45, followed by splitting of …
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