- Design of "click" Fluorescent Labeled 2′-deoxyuridines via C5-[4-(2-Propynyl(methyl)amino)]phenyl Acetylene as a Universal Linker: Synthesis, Photophysical Properties, and Interaction with BSA
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Microenvironment-sensitive fluorescent nucleosides present attractive advantages over single-emitting dyes for sensing inter-biomolecular interactions involving DNA. Herein, we report the rational design and synthesis of triazolyl push-pull fluorophore-la
- Bag, Subhendu Sekhar,Gogoi, Hiranya
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p. 7606 - 7621
(2018/06/18)
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- Asymmetric cross-dehydrogenative coupling enabled by the design and application of chiral triazole-containing phosphoric acids
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This report describes the development of an enantioselective C-N bond-forming reaction to produce 1,2,3,4-tetrahydroisoquinoline-derived cyclic aminals catalyzed by chiral phosphate anions. Central to the success of this goal was the design of a library of 3,3′-triazolyl BINOL-derived phosphoric acids capable of forming attractive hydrogen-bonding interactions with the peptide-like substrate. We envision this work will offer an alternative to the conventional strategy of increasing catalyst steric bulk to improve enantioselectivity with BINOL-derived phosphoric acids.
- Neel, Andrew J.,Hehn, Joerg P.,Tripet, Pascal F.,Toste, F. Dean
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supporting information
p. 14044 - 14047
(2013/10/21)
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- Tunable star-shaped triphenylamine fluorophores for fluorescence quenching detection and identification of nitro-aromatic explosives
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Triphenylamine-based fluorophores containing pyrene or corannulene show variable fluorescence quenching sensitivity toward nitro explosives. The most sensitive fluorophore is capable of detecting TNT on the ng cm-2 scale; the array is useful for identifying nitro aromatics.
- Niamnont, Nakorn,Kimpitak, Nattaporn,Wongravee, Kanet,Rashatasakhon, Paitoon,Baldridge, Kim K.,Siegel, Jay S.,Sukwattanasinitt, Mongkol
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p. 780 - 782
(2013/02/23)
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- Sensing of biomolecules and label-free discrimination of DNA containing a triple T-C/T-G mismatch pair with a fluorescence light-up probe, triazolylpyrene (TNDMBPy)
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Binding to the minor groove of calf-thymus DNA (ct-DNA) and strong binding in hydrophobic pocket of bovine serum albumin (BSA), switched-on the fluorescence of smart fluorescent probe, triazolylpyrene (TNDMBPy). Also, a novel label-free strateg
- Bag, Subhendu Sekhar,Kundu, Rajen,Jana, Subhashis
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supporting information
p. 2627 - 2632
(2013/06/26)
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- Fluorometric sensing of Cu2+ ion with smart fluorescence light-up probe, triazolylpyrene (TNDMBPy)
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We report the detection of Cu2+ ion with fluorescence light-up probe, triazolylpyrene (TNDMBPy). Thus, the probe showed a remarkable fluorescence enhancement of both of the monomer and excimer emissions and a 2:1 probe-Cu2+ complexation with high selectivity, high stability constant and low detection limit. Formation of the excimer was also rationalized on the basis of DFT calculation. Our probe is also capable of sensing SDS micelle-encapsulated-Cu2+ ion in aqueous media with high association constant, thus, showing its practical utility. Thus, our probe could be used as an efficient Cu2+ ion selective fluorescence light-up probe, and may find applications in chemical and biological systems.
- Bag, Subhendu Sekhar,Kundu, Rajen,Talukdar, Sangita
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supporting information
p. 5875 - 5879,5
(2020/08/20)
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- Installation/modulation of the emission response via click reaction
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We have demonstrated the installation of a fluorescence property into a nonfluorescent precursor and modulation of an emission response of a pyrene fluorophore via click reaction. The synthesized fluorophores show different solvatochromicity and/or intramolecular charge transfer (ICT) feature as is revealed from the UV-visible, fluorescence photophysical properties of these fluorophores, and DFT/TDDFT calculation. We observed that some of the synthesized fluorophores showed purely ICT character while emission from some of them arose from the LE state. A structureless and solvent polarity-sensitive dual emission behavior was observed for one of the triazolylpyrene fluorophores that contains an electron-donating -NMe2 substituent (fluorophore, 7a). Conversely, triazolylpyrene with an electron-withdrawing -CN group (fluorophore, 7b) showed a solvent polarity-independent vibronic emission. The effect of ICT on the photophysical properties of these fluorophores was studied by fluorescence emission spectra and DFT/TDDFT calculations. Fluorescence lifetimes were also measured in different solvents. All of our findings revealed the delicate interplay of structure and emission properties and thus having broader general utility. As the CT to LE intensity ratio can be employed as a sensing index, the dual emissive fluorophore can be utilized in designing the molecular recognition system too. We envisage that our investigation is of importance for the development of new fluorophores with predetermined photophysical properties that may find a wide range of applications in chemistry, biology, and material sciences.
- Bag, Subhendu Sekhar,Kundu, Rajen
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experimental part
p. 3348 - 3356
(2011/07/06)
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- Remote control on the photochemical rearrangement of 1,6-(N-aryl)aza-[60] fulleroids to 1,2-(N-arylaziridino)-[60]fullerenes by N-substituted aryl groups
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Photochemical rearrangement of 1,6-(N-aryl)aza-[60]fulleroids (1) to 1,2-(N-arylaziridino)-[60]fullerenes (2) depends on the N-aryl substituents remote from the reaction center. A systematic kinetic study of the N-substituents discloses a decrease in the reaction rates of the photochemical rearrangement in the order 1-naphthyl (1b) > 1-pyrenyl (1d) > phenyl (1a) > 2-naphthyl (1e). The large substituent effect in the rates, which vary by ca. 2200-fold, is interpreted in terms of changes in the reaction mechanisms. The fast photochemical rearrangement of derivatives 1b,d proceeds through the normal triplet states of 1; in the case of 1b, triplet sensitization by the product 2b also operates. For the slow rearrangement rates of 1a.c, nanosecond transient absorption spectroscopy reveals that different triplet states participate, namely, electron transfer between the N-aryl substituent and the fullerene.
- Ouchi, Akihiko,Awen, Bahlul Z. S.,Hatsuda, Ryota,Ogura, Reiko,Ishii, Tadahiro,Araki, Yasuyuki,Ito, Osamu
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p. 9584 - 9592
(2008/04/18)
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- PHOTOCHEMISTRY OF NAPHTHYL AND PYRENYL AZIDES: CHEMICAL PROPERTIES OF THE TRANSIENT INTERMEDIATES PROBED BY LASER SPECTROSCOPY
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The photochemistry of 1-naphthyl azide, 2-naphthyl azide, 1-pyrenyl azide, and 2-pyrenyl azide was examined in inert (benzene) and reactive (diethylamine) solvents.These studies employ a combination of product analysis, low-temperature spectroscopy, and laser-flash photolysis to reveal the chemical and physical properties of the highly reactive, short-lived intermediates formed in these reactions.In all cases two intermediates account for the observations.One of these is the triplet nitrene and the other is a ground-state singlet transient identified as an azirine.The relationship between these intermediates controls the chemical outcome of the reaction.
- Schrock, Alan A.,Schuster, Gary B.
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p. 5234 - 5240
(2007/10/02)
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