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31.
Roy Sourav Singha Sarkar Sriparna Chakraborty Debashis 《Journal of inclusion phenomena and macrocyclic chemistry》2021,100(1-2):37-37
Journal of Inclusion Phenomena and Macrocyclic Chemistry - A correction to this paper has been published: https://doi.org/10.1007/s10847-021-01060-y 相似文献
32.
Manas Mahapatra Arnab Dutta Joy Sankar Deb Roy Ujjal Das Dr. Snehasis Banerjee Prof. Sanjit Dey Dr. Pijush Kanti Chattopadhyay Prof. Dilip K. Maiti Dr. Nayan Ranjan Singha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(2):502-516
To circumvent costly fluorescent labeling, five nonconventional, multifunctional, intrinsically fluorescent aliphatic terpolymers ( 1 – 5 ) have been synthesized by C−C/C−N-coupled, solution polymerization of two non-emissive monomers with protrusions of fluorophore monomers generated in situ. These scalable terpolymers were suitable for sensing and high-performance exclusion of CuII, logic function, and bioimaging. The structures of the terpolymers, in situ attachment of fluorescent monomers, aggregation-induced enhanced emission, bioimaging ability, and super adsorption were investigated by 1H and 13C NMR, EPR, FTIR, X-ray photoelectron, UV/Vis, and atomic absorption spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy, dynamic light scattering, solid-state fluorescence, fluorescence imaging, and fluorescence lifetime measurements, as well as by isotherm, kinetics, and thermodynamic studies. The geometries and electronic structures of the fluorophores and the absorption and emission properties of the terpolymers were examined by DFT, time-dependent DFT, and natural transition orbital analyses. For 1 , 2 , and 5 , the limits of detection were determined to be 1.03×10−7, 1.65×10−7, and 1.77×10−7 m , respectively, and the maximum adsorption capacities are 1575.21, 1433.70, and 1472.21 mg g−1, respectively. 相似文献
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Prabuddha Bhattacharya Monisha Singha Eshani Das Arundhoti Mandal Manasi Maji Amit Basak 《Tetrahedron letters》2018,59(32):3033-3051
Garratt-Braverman cyclization has emerged as one of the simplest synthetic tool to construct two consecutive CC bonds leading to the formation of various important structural scaffolds having significance in the field of therapeutics and material science. The strategic design of suitable precursor for this cycloaromatization reaction involves the deep understanding of reaction pathways involving diradicals and ions. On the other hand, the reaction offers an unprecedented mechanistic paradox for the chemists to solve. This report aims at outlining the recent mechanistic and synthetic developments with special emphasis on the research outcomes from our laboratory. 相似文献
35.
Maite Nößler René Jäger David Hunger Dr. Marc Reimann Tobias Bens Dr. Nicolás I. Neuman Dr. Arijit Singha Hazari Prof. Dr. Martin Kaupp Prof. Dr. Joris van Slageren Prof. Dr. Biprajit Sarkar 《欧洲无机化学杂志》2023,26(19):e202300091
Due to their ability to form stable molecular complexes that have tailor-made properties, terpyridine ligands are of great interest in chemistry and material science. In this regard, we prepared two terpyridine ligands with two different fluorinated phenyl rings on the backbone. The corresponding CoII and FeII complexes were synthesized and characterized by single-crystal X-ray structural analysis, electrochemistry and temperature-dependent SQUID magnetometry. Single crystal X-ray diffraction analyses at 100 K of these complexes revealed Co−N and Fe−N bond lengths that are typical of low spin CoII and FeII centers. The metal centers are coordinated in an octahedral fashion and the fluorinated phenyl rings on the backbone are twisted out of the plane of the terpyridine unit. The complexes were investigated with cyclic voltammetry and UV/Vis-NIR spectroelectrochemistry. All complexes show a reversible oxidation and several reduction processes. Temperature dependent SQUID magnetometry revealed a gradual thermal SCO behavior in two of the complexes, while EPR spectroscopy provided further insights on the electronic structure of the metal complexes, as well as site of reduction. 相似文献
36.
We have investigated the magnetic properties of four recently synthesized stable TMM-type nitroxide diradicals. Four new diradicals are proposed by tailoring one of the species in such a way that both conjugation and planarity increase. As a remarkable consequence, the intramolecular ferromagnetic exchange interaction was found to be quite high in the proposed radicals. The calculated coupling constants were in the range of +102 to +140 cm-1. The MO and spin density analysis are provided to interpret the exchange interactions. We observed the existence of intramolecular pi-pi-interactions for the species 2. This slightly increased the J value by shortening the length of the spacer between the two spin sources. 相似文献
37.
S.M. Islam Anupam Singha Roy Paramita Mondal Kazi Tuhina Manir Mobarak John Mondal 《Tetrahedron letters》2012,53(2):127-131
A new polymer-anchored Cu(II) complex has been synthesized and characterized. The catalytic performance of the complex has been tested for the oxidation of sulfides and in oxidative bromination reaction with hydrogen peroxide as the oxidant. Sulfides have been selectively oxidized to the corresponding sulfoxides in excellent yields and in the presence of KBr as the bromine source, organic substrates have been selectively converted to mono bromo substituted compounds using polymer-anchored Cu(II) catalyst. This catalyst showed excellent catalytic activity, high selectivity, and recyclability. The polymer-anchored Cu(II) catalyst could be easily recovered by filtration and reused more than five times without appreciable loss of its initial activity. 相似文献
38.
Atom transfer radical polymerization (ATRP) of ethyl acrylate was carried out in bulk using ethyl 2-bromoisobutyrate as initiator, CuBr as well as CuCl as catalyst in combination with different ligands e.g., 2,2′ bipyridine (bpy)andN,N, N′,N″,N″-pentamethyldiethylenetriamine (PMDETA). In most of the cases very high conversion (72–98%) was achieved. The polymerization was well controlled with a linear increase of molecular weight (MnSEC) with conversion and relatively narrow molecular weight distributions (polydispersity index 1.2–1.3). Use of PMDETA as the ligand resulted in faster polymerization rate (98% conversion in 1 h) than those using bipyridine (72% conversion in 5 h). The MALDI-TOF-MS analysis of poly (ethyl acrylate) (PEA) prepared by using bpy as ligand showed the presence of halogen as the end group. On the contrary, when PMDETA was used as the ligand, the mass analysis showed no trace of this end group. 相似文献
39.
Minu Chaudhuri Ujjal K. Singha Boden H. Vanderloop Anuj Tripathi W. David Nes 《Molecules (Basel, Switzerland)》2022,27(13)
Trypanosoma brucei, the causative agent for human African trypanosomiasis, is an emerging ergosterol-dependent parasite that produces chokepoint enzymes, sterol methyltransferases (SMT), not synthesized in their animal hosts that can regulate cell viability. Here, we report the lethal effects of two recently described natural product antimetabolites that disrupt Acanthamoeba sterol methylation and growth, cholesta-5,7,22,24-tetraenol (CHT) and ergosta-5,7,22,24(28)-tetraenol (ERGT) that can equally target T. brucei. We found that CHT/ERGT inhibited cell growth in vitro, yielding EC50 values in the low nanomolar range with washout experiments showing cidal activity against the bloodstream form, consistent with their predicted mode of suicide inhibition on SMT activity and ergosterol production. Antimetabolite treatment generated altered T. brucei cell morphology and death rapidly within hours. Notably, in vivo ERGT/CHT protected mice infected with T. brucei, doubling their survival time following daily treatment for 8–10 days at 50 mg/kg or 100 mg/kg. The current study demonstrates a new class of lead antibiotics, in the form of common fungal sterols, for antitrypanosomal drug development. 相似文献
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