PRASENJIT MAITY
Articles written in Journal of Chemical Sciences
Volume 121 Issue 4 July 2009 pp 377-385
Prasenjit Maity Double Mukesh Sumit Bhaduri Goutam Kumar Lahiri
A series of water soluble Keggin type heteropolyoxotungstates have been tested as oxidation catalysts in aqueous-biphasic media with dilute H2O2 (30%) as the oxygen atom donor, without using any phase transfer agent. The Zn substituted polyoxoanion {(NH4)7Zn0.5[𝛼-ZnO4W11O30ZnO5(OH2)]$.n$H2O} has been found to be the most efficient catalyst, which oxidizes a wide range of organic functionalities with good turnovers and high selectivities. The functionalities that undergo oxidations are: organic sulfides, pyridines, anilines, benzyl alcohols and benzyl halides. The oxidations of sulfides to sulfoxides and/or sulfones have been studied in detail, and a simple kinetic model consisting of two consecutive reactions, is shown to give good fit with the experimental data. In the catalytic system described here product isolation is easy, and the aqueous catalyst solution can be re-used several times with little loss in its efficiency.
Volume 131 Issue 2 February 2019 Article ID 0014
PRANAV DAVE BHAVESH AGRAWAL JAYDEV THAKARDA SAGAR BHOWMIK PRASENJIT MAITY
9-Ethynylphenanthrene (EPT) bound to highly monodispersed Ruthenium (Ru) nanocluster (Ru:EPT) with mean diameter of 1.5 ± 0.2 nm and mol wt. of ~8600 Da was synthesized
Volume 133 All articles Published: 13 July 2021 Article ID 0072
JASMIN KUBAVAT JAYDEV THAKARDA TUSHAR TYAGI SAGAR BHOWMIK PRASENJIT MAITY
Here we report fluorescence quenching based detection of selected ‘‘Thiol’’ molecules byemploying a luminescent gold cluster through ligand displacement strategy. First, an aryl iodide (2-Iodonaphthalene,NP) and polyvinylpyrrolidone (PVP) mixed ligand stabilized gold cluster was synthesized with astrong fluorescence signal originated from excimer of 2-Iodonaphthalene ligands grafted on gold nano surface.Among different small molecule-based ligands, thiol (R-SH) forms a strong bond with gold nanoparticles.Anticipating this property, we have found that displacement of 2-Iodonaphthalene ligand from goldnanoparticle surface by thiols results in the sensitive detection of thiols through the quenching of emission ofgold cluster. The selectivity for detection of different tested analytes follows the order: GSH>Cys>hCywhereas, other non-thiol based amino acids and common salts are innocent towards fluorescence response.Easy synthesis of the fluorescent gold cluster, selective sensing of small thiol molecules, high Stern-Volmerconstant (KSV=3.3×106 M-1) and ultralow detection limit (LOD of 35 nM) are notable features of the presentreport.
A fluorescence turn-off chemosensor has been developed for sensing selected
Volume 135, 2023
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