PAWAN KUMAR
Articles written in Journal of Chemical Sciences
Volume 126 Issue 1 January 2014 pp 33-40
N′, N″, N‴-tris(2-pyridyloxymethyl) ethane as ionophore in potentiometric sensor for Pb(II) ions
Pawan Kumar Ashok Kumar S K Susheel K Mittal
N′,N″,N‴ tris(2-pyridyloxymethyl) ethane (TPOME) has been used as an ionophore in a polyvinylchloride (PVC)-based membrane. Membrane electrode with a composition 30:5:62:3 (PVC:TPOME: o-NPOE:NaTPB) exhibits Nernstian response towards Pb(II) ions with a slope of 30mV/decade, over a concentration range of $1 \times 10^{−5}$ M to $1 \times 10^{−1}$ M. Potential response remains almost unchanged over pH range of 3.7-6.4. The electrode shows fast response time of $15 \pm 2$ s and a lifetime of four months. It shows good selectivity for Pb(II) ions over other mono-, di- and trivalent cations. Electrode response is satisfactory in mixed solvent media up to 30% (v/v) non-aqueous contents. Selectivity of the ionophore for Pb(II) ions was determined by spectrophotometric method. The electrode can also be used as an indicator electrode in potentiometric titration of Pb(II) ions with standard chromate solution and its determination in real-life samples. Surface morphology of membrane electrode at different stages of its development and use is also discussed.
Volume 126 Issue 3 May 2014 pp 711-716 Regular Articles
Maruthai Kumaravel Pawan Kumar Maravanji S Balakrishna
The bisphosphomide-based pincer complex [PdBr{2,6-{Ph2PC(O)}2(C6H3)}] (
Volume 130 Issue 7 July 2018 Article ID 0092
Reactions of 4-diphenylphosphino benzoic acid with organotin oxides and -oxy-hydroxide
RAMAKIRUSHNAN SURIYA NARAYANAN PAKKIRISAMY THILAGAR JOYDEV ACHARYA PAWAN KUMAR DODDAPUNENI KRISHNA RAO VADAPALLI CHANDRASEKHAR ANUKUL JANA
The reactions of p-diphenylphosphinobenzoic acid (LCOOH) with various organotin precursors have been carried out. Accordingly, the reaction of [n-BuSn(O)(OH]n with LCOOH afforded the hexameric compound, [n-BuSn(O)O2C–C6H4–p-PPh2]6(1). On the other hand, the reaction of LCOOH with [n-Bu2SnO]n gave the tetrameric compound [{n-Bu2SnO2C–C6H4–p-PPh2}2O]2 (2). The 1-D coordination polymers [R3SnO2C–C6H4–p-P(O) Ph2]n,[ R=n-Bu (3), R=Ph (4)] were prepared in the reaction of [n-Bu3Sn]2O or [Ph3Sn]2O with LCOOH. The compounds 1–4 were structurally characterized by multinuclear NMR spectroscopic and single crystal X-ray diffraction studies
Volume 135 All articles Published: 25 March 2023 Article ID 0021
Imine linked AntiBSA@NUS-15 for molecular sensing applications
1,3,5-tris-(4 formyl phenyl) benzene and p-Phenylenediamine based covalent organic framework(COF) i.e., National University of Singapore-15 (NUS-15) have been synthesized using the solvothermal method at room temperature. Importantly, synthesized NUS-15 has been analysed using powdered X-ray diffraction (PXRD), Field emission scanning electron microscopy (FE-SEM), Infrared and UV-Visible spectroscopy techniques. Afterward, the optical properties of NUS-15 (excitation wavelength = 298 nm,emission wavelength = 404 nm) were confirmed through a photoluminescence spectrophotometer. Later on,biofunctionalization of NUS-15 was performed with Anti-BSA using coordination chemistry and confirmed through various analysis techniques. Based on optical properties, NUS-15-based Bioconjugate i.e., Anti-BSA@ NUS-15, has been utilized for selective sensing applications and noted 0.366 ppm detection limit for BSA. Our results imply that NUS-15 might be applied in future biomedical applications.
Synopsis. In this work, a covalent organic framework i.e., NUS-15 was synthesised and characterised for Anti-BSA tagged through simple coordination chemistry. Later, Anti BSA-tagged NUS-15 was explored for selective BSA sensing in a certain range using a photoluminescence spectrophotometer. Our results confirm 1.11 ppm (limit of quantification) and 0.366 ppm (limited of detection) during BSA detection.
Volume 135 All articles Published: 12 August 2023 Article ID 0085
Optical detection of nitroaromatic compounds using MAPbBr3 at room temperature
Methylammonium lead bromide, i.e., MAPbBr3, has been synthesized at room temperature through chemical stirring method. The structural characterization of synthesized MAPbBr3 has been confirmed through X-ray diffraction technique, Field emission scanning electron microscopy, Fourier transform infrared, thermo gravimetric analysis and UV-Vis spectroscopy. Afterward, the optical properties (excitation wavelength 415 nm; emission wavelength = 535 nm) of MAPbBr3 were confirmed through a photoluminescence spectrophotometer. To end, MAPbBr3 has been used for the optical detection of nitroaromatic compounds, i.e., nitrobenzene (NB), dinitrobenzene (DNB), dinitrotoluene (DNT), trinitrophenol (TNT) inhexane. Our research has confirmed the 7.1 ppb and 10 ppb detection limit (LOD) for nitrobenzene and dinitrobenzene only using MAPbBr3, respectively. Importantly, we found out the selectivity %, i.e., 1.3% and2.7% in the case of nitrobenzene and dinitrobenzene sensing using MAPbBr3 in hexane, respectively.
SYNOPSIS * Synthesis and analysis of MAPbBr3, i.e., metal halide perovskite (MHPs), has been performed at room temperature through the chemical stirring method. * MAPbBr33 has been used for optical sensing of nitroaromatic compounds, i.e., nitrobenzene (NB), dinitrobenzene (DNB), dinitrotoluene (DNT), trinitrophenol (TNT) in hexane. * We have achieved 7.1 ppb and 10 ppb limit of detection (LOD) with selectivity %, i.e., 1.3% and 2.7% for nitrobenzene and di-nitrobenzene only using MAPbBr3, respectively.
Volume 135, 2023
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