Browsing by Author "Mrituanjay D. Pandey"

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A highly efficient nanostructured Au@La2O3 based platform for dopamine detection
(Elsevier B.V., 2022) Ankur Srivastava; Gargi Mishra; Jay Singh; Mrituanjay D. Pandey
In the present work, nanostructured La2O3 and Au doped La2O3 nanocomposites were prepared hydrothermally that were further deposited electrophoretically onto the indium-tin-oxide (ITO) glass surface. The tyrosinase enzyme (Tyr) have been immobilized on the AuNPs modified La2O3/ITO electrode. The fabricated electrode Tyr/Au-La2O3/ITO was utilized for the determination of dopamine. The structural and morphological characterization were done by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Atomic force microscopy (AFM), Transmission electron microscopy (TEM & HR-TEM) and Energy dispersive X-ray analysis (EDX). The results of electrochemical response studies of fabricated electrode Tyr/Au-La2O3/ITO exhibit a linear range of 2–100 µm, sensitivity 2.4806 × 10−7 A/μM and limit of detection of 0.258 μM with response time 30 s and good reproducibility. The fabricated electrode might provide an efficient biointerface for the application of the rare earth metal oxide nanomaterials in biosensors and bioelectronics. © 2021 Elsevier B.V.
A luminescent pyrene-valine conjugates for the detection of copper (II) ions in aqueous media
(Elsevier B.V., 2023) Kamlesh Kumar Nigam; Arpna Tamrakar; Gargi Mishra; Mrituanjay D. Pandey
A novel pyrene-based fluorescent chemosensor (pyren-1-ylmethyl)-L-valine (1) has been synthesized. 1 is a highly selective chemosensor for detecting Cu(II) ions through fluorescence quenching over other competitive metal ions and showing aqueous-organic solvent-based gelation properties. Rod-shaped surface morphology may be attributed to intermolecular Hydrogen bonding between the carboxylic acid group and π-π stacking of pyrene moiety. In addition, 1 can also be utilized for the practical detection of Cu2+ion in natural water samples. © 2023 The Authors
A uniquely fabricated Cu(II)-metallacycle as a reusable highly sensitive dual-channel and practically functional metalloreceptor for Fe3+ and Ca2+ ions: An inorganic site of cation detection
(Royal Society of Chemistry, 2018) Neha Thakur; Mrituanjay D. Pandey; Rampal Pandey
The present study deals with the formation of cyanuric chloride·1,2-di(pyridin-2-yl)disulfane 1 co-crystal and trimethylcyanuric acid 2 through unusual reactions of cyanuric chloride (CC). Reaction of co-crystal 1 with Co(ii) and Cu(ii) led to the formation of di(pyridin-2-yl)sulfane 1′ through a desulfurization reaction and complexes [Co(1′)Cl2] (3) and [Cu(1′)2-(μ2-SO4)2(H2O)2] (4). The structures of 1-4 were verified using X-ray single crystal analysis. The Cu(ii)-metallacycle 4 acts as a dual-channel metalloreceptor for Fe3+ and Ca2+ through a fluorescence 'turn-on' response for Ca2+, a 'turn-off' response for Fe3+, and changes in cyclic voltammograms in pure aqueous-buffer medium (1.0 M Tris-HCl, pH 7.4). The limits of detection (LOD) for Fe3+ and Ca2+ were estimated to be 30 ppb and 0.2 ppm, respectively. For the first time, the EPR technique was applied to detect a paramagnetic ion (Fe3+) using a paramagnetic probe (4), which exhibited considerable change upon interaction with Fe3+. Further, structural elucidation of 4, use of Co(ii)-complex 3 as a model compound, and FTIR and mass spectral studies suggested that the detection of cations by Cu(ii)-metallacycle 4 occurs through its unique inorganic detection site (six oxygen atoms from sulphate and water groups). Due to its higher selectivity of Fe3+ over Ca2+ and other metal ions as well as its LOD for Fe3+, which is lower than the US Environmental Protection Agency permitted maximum level in drinking water (5.4 μmol L-1), 4 was successfully used for practical detection of Fe3+ in environmental water samples. The exceptionality of this report comprises the detection of vital cations using a binuclear Cu(ii) metallacycle probe, utilizing the EPR technique, binding through an inorganic site and the practical application of 4 toward Fe3+ sensing. © 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
A zinc (II) complex comprising an aminoethyl-nitropyridine-derived N,N,O-donor Schiff base ligand serves as an efficient ON–OFF probe for Cu(II)
(John Wiley and Sons Ltd, 2023) Himani Sharma; Arpna Tamrakar; Tarkeshwar Maddeshiya; Pawan Raj Shakya; Kamal Kant Tiwari; Mrituanjay D. Pandey; Rampal Pandey
A new fluorescent zinc (II) complex-based probe 1 encompassing a Schiff's base (E)-2-methoxy-6-((2-[5-nitropyridin-2-ylamino]ethylimino)methyl)phenol (HL) was designed, synthesized, and used for the highly selective detection of Cu2+. Ligand HL and complex 1 were characterized using various spectroscopic techniques such as 1H, 13C-NMR, and FTIR spectroscopy, high-resolution mass spectronomy (HRMS), UV/visible light spectroscopy, and fluorescence studies. Ligand HL did not exhibit any considerable change in fluorescence in the presence of various cations. Notably, its Zn(II) complex 1 exhibited highly selective ‘TURN-OFF’ fluorescence signalling towards Cu2+ that remained uninterrupted with competing analytes. Probe 1 interacted with Cu2+ in 1:2 (1:Cu2+) stoichiometry as estimated through a Job's plot. Moreover, the selectivity of 1 was further confirmed through the interaction of the 1 + Cu2+ complex with some possible interfering metal ions inducing an insignificant response. Additionally, the association and quenching constant were determined to be 3.30 × 104 M−1 and 0.21 × 105 M−1 through the Benesi–Hildebrand method and Stern–Volmer plot, respectively. © 2022 John Wiley & Sons Ltd.
Advancements in the Design and Development of Organic Fluorophores for the Excited State Intramolecular Proton Transfer Phenomenon
(John Wiley and Sons Inc, 2025) Gargi Mishra; Durgesh Singh; Surabhi Asthana; Himanshu Shekhar Tripathi; Rampal Pandey; Mrituanjay D. Pandey
Excited state intramolecular proton transfer (ESIPT) is a process where photoexcited molecules dissipate energy by transferring protons and undergoing tautomerization. With a brief introduction of a new emerging sensing mechanism, viz., C.N isomerization, AIE, etc., this study explores the various aspects of ESIPT based on the current studies. Since Weller discovered ESIPT in salicylic acid and methyl salicylate, extensive research has developed on this topic, attributing to its wide applications. Here, it explores the structural and mechanical aspects of ESIPT and tautomerization. © 2025 The Chemical Society of Japan and Wiley-VCH GmbH.
Advancements in the development of fluorescent chemosensors based on C=N bond isomerization/modulation mechanistic approaches
(Royal Society of Chemistry, 2024) Arpna Tamrakar; Manzoor Ahmad Wani; Gargi Mishra; Ankur Srivastava; Rampal Pandey; Mrituanjay D. Pandey
The C N bond isomerization/modulation as a fluorescence signalling mechanism was explored by studying the photophysical properties of conformationally restricted molecules. From the beginning, the C N bond isomerization method has attracted the attention of researchers owing to its simplicity, high selectivity, and sensitivity in fluorescence evaluation. Continuous developments in the field of sensing using C N bond-containing compounds have been achieved via the customization of the isomerization process around the C N bond in numerous ways, and the results were obtained in the form of specific discrete photophysical changes. C N isomerization causes significant fluorescence enhancement in response to detected metal cations and other reactive species (Cys, Hys, ClO−, etc.) straightforwardly and effectively. This review sheds light on the process of C N bond isomerization/modulation as a signalling mechanism depending on fluorescence changes via conformational restriction. In addition, C N bond isomerization-based fluorescent sensors have yet to be well reviewed, although several fluorescent sensors based on this signalling mechanism have been reported. Therefore, C N-based fluorescent sensors are summarized in this review. © 2024 The Royal Society of Chemistry.
Aloe vera gel (Aloe barbadensis miller) derived self-assembled flower-shaped carbon quantum dot interface for ultra-sensitive electrochemical detection of the endocrine disruptor bisphenol-A
(Royal Society of Chemistry, 2024) Ankur Srivastava; Kshitij RB Singh; Khrsheed Ahmed; Ravindra Pratap Singh; Mrituanjay D. Pandey; Shyam S. Pandey; Jay Singh
This manuscript is focused on the synthesis of biologically derived carbon quantum dots (CQDs) via hydrothermal methods using Aloevera leaves (Aloe barbadensis miller). The proposed biochemical route, utilizing Aloevera gel, has garnered attention due to its cost-effectiveness, eco-friendly nature, and ability to produce highly pure, stable, and fluorescent biologically derived self-assembled nanoparticles measuring approximately 5-6 nm in size. The primary objective was to harness plant sources and establish a sustainable and renewable platform for synthesizing valuable nanostructures, encouraging researchers to shift their focus from unhealthy chemicals to natural resources for healthier and non-polluting investigations. The synthesized CQDs exhibited remarkable colloidal properties, excellent fluorescence, and photostability under UV light. Characterization techniques such as powder XRD, UV-Vis spectroscopy, photoluminescence, FT-IR, AFM, and TEM were employed to analyse the prepared CQDs. Furthermore, the prepared CQDs displayed significant electrochemical behaviour in the presence of tyrosinase enzyme to detect Bisphenol-A, which functions as an endocrine disruptor (ED). These nanomaterials were also utilized for electrochemical biosensing applications. Additionally, the fabricated CQDs exhibited unique structural and morphological characteristics, along with efficient electrochemical properties, which are thoroughly discussed in the manuscript. © 2024 The Royal Society of Chemistry
Carbazole-isonicotinoyl Hydrazone and Its Structurally Distinct Zinc(II) Complexes as Reversible Mechanochromic, Mechanofluorochromic, and Acidochromic Smart Materials
(American Chemical Society, 2024) Himani Sharma; Tarkeshwar Maddeshiya; Mrituanjay D. Pandey; Rampal Pandey
A new donor-acceptor type hydrazone (HL), namely, (E)-N′-((9-ethyl-9H-carbazol-3-yl)methylene)isonicotinohydrazide comprising carbazole as donor and isonicotinoyl group as acceptor unit and its two Zn(II)-complexes 1 and 2 have been synthesized and characterized by elemental analysis, FT-IR, 1H and 13C NMR, and mass spectral techniques. Complexes 1 and 2 have been synthesized using the same ligand, HL, and zinc metal ion by treating ZnCl2 and Zn(NO3)2·6H2O, respectively. The structure of HL was confirmed by single-crystal X-ray diffraction analysis. Comprehensive photophysical properties of HL, 1, and 2 revealed remarkable reversible mechanochromic luminescent behavior of HL and 1 on grinding, whereas 2 remains nonresponsive toward mechanical force stimuli. Notably, under UV light irradiation (365 nm), the solid-state emission color of pristine HL changes from blue to yellowish green after grinding, while the luminescence color of 1 transforms from yellow to orange. In addition, HL and 1-2 also exhibit acidochromic behavior on exposure to HCl/NH3 vapors. Notably, the mechanofluorochromism and the acidochromism of HL and 1 have been thoroughly studied by PXRD, TGA, and DSC studies and fluorescence lifetime measurements. Further, the structural chemistry involved in these behaviors has been thoroughly explored and emphasized that even a small structural variation can significantly alter the photophysical properties of organic and inorganic materials. © 2024 American Chemical Society.
Carbonaceous Catalysts for Pollutant Degradation
(wiley, 2023) Poonam Kaswan; Santimoy Khilari; Ankur Srivastava; Girijesh Kumar; Pratap K. Chhotaray; Mrituanjay D. Pandey; Kamalakanta Behera
To enhance the quality of the environment, a lot of studies have been done on carbonaceous materials to develop different architectures and qualities. The development and importance of carbonaceous photocatalysts is briefly highlighted in this chapter, which also includes different semiconductors based on activated carbon, carbon nanotubes, carbon dots, fullerene, graphene, aerogels and carbon sponges, etc. In the present chapter, we have considered two types of strategies to discuss the entitled topic, one is a carbon-based catalyst, and the second is carbonaceous material with other metal composites to enhance the activity. Various difficulties with a metal catalyst, such as limited light adsorption capacity, large band gap energy, and insufficient physicochemical stability, continue to severely restrict photocatalysts for practical uses. To get rid of this, some unique catalysts based on carbon materials have been designed and inserted into a photocatalytic system to enhance activity. They are found to be ideal for various types of applications ranging from the field of renewable energy to waste water management and treatment, thanks to the synergistic combination of metal nanoparticles and carbonaceous nanostructures. Carbon-based metal nanostructures are much essential to dissolve a variety of colorful and colorless hazardous contaminants, such as organic dye, NOXelimination, water splitting, etc., when they are subjected to visible light. © 2023 Scrivener Publishing LLC.
Click Chemistry - Inspired Synthesis of Porphyrin Hybrid Glycodendrimers as Fluorescent Sensor for Cu(II) Ions
(John Wiley and Sons Inc, 2022) Anand K. Agrahari; Sunil Kumar; Mrituanjay D. Pandey; Sanchayita Rajkhowa; Manoj K. Jaiswal; Vinod K. Tiwari
An expeditious and modular CuAAC ‘click’ protocol has been exploited for the construction of porphyrin cored hybrid glycodendrimers of G1 and G2 generation. The developed porphyrin hybrid glycodendrimers were characterized using extensive spectral analysis including NMR (1H, 13C, and 19F), MS, MALDI-TOF, IR, and SEC datas and evaluated for their sensing ability for a range of metal ions, where they displayed notable sensing for Cu(II) ion with solvatochromism properties. © 2022 Wiley-VCH GmbH.
Click Chemistry-Inspired Synthesis and Photophysical Studies of Calix[4]arene-Cored Galactosylated and Mannosylated Glycodendrimers
(Georg Thieme Verlag, 2022) Sunil Kumar; Mangal S. Yadav; Tarkeshwar Maddeshiya; Surabhi Asthana; Manoj K. Jaiswal; Vinod K. Tiwari; Mrituanjay D. Pandey
A prompt and modular copper(I)-catalyzed azide-alkyne cycloaddition click approach has been exploited for the synthesis of galactose- and mannose-coated calixarene-cored G1 generation glycodendrimers. The developed calixarene glycodendrimers were characterized by using spectral techniques (1H NMR, 13C NMR and IR). In photophysical evaluation, UV and fluorescence spectra of the developed compounds were recorded in CH3CN/H2O. © 2023. The Author(s).
Co(II)-catalyzed decarboxylation of itaconic acid engendering methacrylic acid and Co(II)-MOFs for structure regulated fluorescent detection of cations
(Academic Press Inc., 2019) Neha Thakur; Mrituanjay D. Pandey; Rampal Pandey
Hydrothermal synthesis of a common value added product methacrylic acid (MAA) via Co(II)-catalyzed decorboxylation of itaconic acid (IA), along with formation of two Co(II)-MOFs [(CH3)2NH2]+[Co(HCOO)3]n − 1 and [Co(HCOO)2(μ-HCOO)Co(HCOO)(H2O)4]n 2, has been reported. Identical reactants and conditions (except bases) ensued in the formation of an ionic MOF 1 and a neutral MOF 2 wherein HCOO− ligands assume W- and W + U-bridging modes, respectively. SEM, TEM, AFM and BET surface area also revealed morphological differences in 1 and 2. UV/vis, fluorescence and sensing behavior of any perovskite type [M(HCOO)x]n MOF have been explored for the first time. MOFs 1 and 2 are water stable, fluorescent and exhibit structure regulated cations detection; MOF1 for Fe3+ (turn-off) and Hg2+ (turn-on); MOF2 for Fe3+ (turn-off) and Cu2+ (turn-off). Both 1 and 2 display very high selectivity, sensitivity (10–100 ppb) and good reusability. Overall, novel findings are; high yield production of industrially important MAA via selective catalytic decomposition of IA, mechanistic evidence through formation of Co(II)-MOFs, structurally different Co(II)-MOFs obtained under identical conditions, water stability of MOFs, and distinctive morphological, optical and cation sensing behavior of 1 and 2. © 2019 Elsevier Inc.
Copper-guided tuning of supramolecular nano-assembly in pseudopeptide-based soft bioinspired materials
(Royal Society of Chemistry, 2023) Arpna Tamrakar; Kamlesh Kumar Nigam; Mrituanjay D. Pandey
Pseudopeptide-based soft bioinspired materials have recently emerged as state-of-the-art soft matter for recognition and supramolecular self-assembly. Therefore, we synthesized l-valine and l-phenylalanine-based C2-symmetric pseudo-peptidic soft bioinspired materials for the selective and sensitive detection of Cu(ii) ions in aqueous-organic media through the CHEQ mechanism. These pseudopeptides show 2 : 1 stoichiometry with Cu(ii), with a high value of binding constant (Ka = 0.035 × 105 M−1, 0.02 × 105 M−1) and low detection (0.053 ppm and 0.0047 ppm), respectively, for 1 and 2. Also, the Cu(ii) guided tuning of supramolecular nano-assembly is a promising field for material nano-architectonics applications. © 2023 The Royal Society of Chemistry
Cyclometalated Ir(III) Complex as a Metalloligand and a Selective Cu(II) Sensor: Synthesis and Structural Characterization of a Heterometallic Tetranuclear Ir(III)/Cu(II) Complex
(American Chemical Society, 2018) Vadapalli Chandrasekhar; Bani Mahanti; Mrituanjay D. Pandey; R. Suriya Narayanan
A cyclometalated Ir(III) complex, [Ir(ppy)2(LH)] (2) [LH2 = 1,2-bis(pyridine-2-carboxamido)benzene; ppyH = 2-phenylpyridine] was synthesized and structurally characterized. [Ir(ppy)2(LH)] contains free donor sites and functions as a metalloligand. Accordingly, it interacts with a Cu(II) salt to afford the heterometallic tetranuclear complex, [{Ir(ppy)2(L)}2{Cu2Cl2}] (3). In the latter, a Cu2Cl2 dimer bridges the two cyclometalated Ir(III) units, resulting in a IrIII-CuII-CuII-IrIII motif. 2 also functions as a selective and reversible sensor for Cu2+, as revealed by quenching of its emission and subsequent revival of the luminescence signal upon addition of EDTA. © 2018 American Chemical Society.
Design of C2-symmetric pseudopeptides for in vivo detection of Cu(ii) through controlled supramolecular nano-assembly
(Royal Society of Chemistry, 2024) Arpna Tamrakar; Surabhi Asthana; Praveen Kumar; Neha Garg; Mrituanjay D. Pandey
Pseudopeptides are emerging next-generation soft bioinspired materials for biological applications. Therefore, a new class of C2-symmetric l-valine-derived pseudopeptides has been designed and developed. The newly developed pseudopeptides exhibit intracellular Cu(ii) ion detection in live-cell fluorescence studies on RAW264.7 cells. We find that the changes in the amino acid side chain in desired pseudopeptidic moieties lead to a drastic change in their selectivity towards different metal ions. The l-valine-derived pseudopeptides exhibit selectivity towards Cu(ii) ions through turn-off fluorescence, and the l-phenylalanine-derived pseudopeptides exhibit selectivity towards Zn(ii) ions through turn-on fluorescence. In addition, the l-valine-derived pseudopeptides show an increase in spherical-shaped structures upon incubation with Cu(ii) ions during supramolecular nano-assembly formation. In contrast, the l-phenylalanine-derived pseudopeptides show a decrease in spherical-shaped structures upon adding Zn(ii) ions. The judiciously designed l-valine-derived and l-phenylalanine-derived bioinspired pseudopeptides are promising for exploring similar effects in various peptidomimetics in advanced biological applications. © 2024 The Royal Society of Chemistry.
Development of highly selective fluorescent ferrocenyl-iminopyridine chemosensor for biologically relevant Fe3+
(John Wiley and Sons Ltd, 2023) Himani Sharma; Vaishali Singh; Arpna Tamrakar; Kamlesh Kumar Nigam; Mrituanjay D. Pandey; Kamal Kant Tiwari; Rampal Pandey
Design, synthesis, characterization, and ion detection studies of two ferrocene-appended Schiff bases namely N-(2-[ferrocenylamino]ethyl)-5-nitropyridin-2-amine (1) and ferrocenylamino-1H-imidazole-4-carboxamide (2) been reported. Both the chemosensors have been thoroughly characterized using Fourier transfer infrared, 1H and 13C nuclear magnetic resonance, high resolution mass spectrometry, and ultraviolet/visible (UV/visible) and fluorescence spectral techniques. Probes 1 and 2 were designed with the aim of appending the ferrocenyl group with pyridine ring having an amine substitution (for 1) and imidazole ring with an amide substitution (for 2). Interaction of these probes with a series of cations and anions was examined through UV/vis and fluorescence spectral techniques. Probe 2 exhibited an insignificant response towards anions and loss of selectivity for cations, whereas 1 displayed highly selective detection towards biologically important Fe3+ in 2:1 (probe:cation) stoichiometry. Notably, none of the cations and anions could interfere the selectivity of Fe3+ ensured by 1 in aqueous medium. The limit of detection for Fe3+ detection using 1 was determined to be 0.2 ppm. The results strongly suggest that 1 could find promising future application as a chemosensor for Fe3+ in biological systems for quantification and qualitative analysis. © 2022 John Wiley & Sons Ltd.
Efficient removal of chromate from wastewater using a one-pot synthesis of chitosan cross-linked ceria incorporated hydrous copper oxide bio-polymeric composite
(Elsevier B.V., 2024) Ayan Ghosh; Sumana Mondal; Sarat Kanrar; Ankur Srivastava; Mrituanjay D. Pandey; Uday Chand Ghosh; Palani Sasikumar
Remediating hexavalent chromium [Cr(VI)] from contaminated water systems is a significant concern due to its harmful effects on human health, aquatic life, and plants. To tackle this issue, scientists have created a chitosan cross-linked hydrous ceria incorporated cupric oxide bio-polymeric composite (CHCCO) by combining chitosan biopolymer with corresponding metal ions using glutaraldehyde as a cross-linker. The composite was characterized using advanced analytical instruments such as FTIR, p-XRD, SEM, XPS, etc. The synthesized composite (CHCCO) was then tested for its efficiency in removing Cr(VI) from synthetic Cr(VI) aqueous samples. The parameters examined included pH, material dose, contact time, concentration, temperature, and co-existing ions. The experimental data showed that the kinetics and equilibrium data fit well with the pseudo-second-order and the Freundlich isotherm models, respectively. Thermodynamic analysis demonstrated that the investigated surface adsorption process is spontaneous and endothermic. Except for the SO42− ion, no other species imparts adverse influence significantly on the reaction. The CHCCO bio-composite surfaces were refreshed using a dilute NaOH (1.0 M) solution and effectively recycled five times for Cr(VI) adsorption, indicating no significant surface activity deterioration. This study highlights the high effectiveness of CHCCO bio-polymeric composites in Cr(VI) remediation and the potential for this technology as an easy-to-use technique for environmental restoration. © 2024 Elsevier B.V.
Electronic metal-organic framework sensors
(wiley, 2023) Ankur Srivastava; Rahul Verma; Gargi Mishra; Jay Singh; Mrituanjay D. Pandey
Metal-organic frameworks (MOFs) are well-ordered and managed inorganic and organic molecules or complexes with large surface area and also the porosity. The size and shape is tunnel-like, having host-guest relations causes both physical and chemical sensitivity, such as temperature, pressure, pH, and light. These are active materials in device manufacturing, such as radiation detectors, chemical sensors, photodetectors, and various more. Electronic area and sensor devices are the new generations' research challenges. The hybrid creations in MOFs are also a new working field these days. In the present book chapter, we sum up the basic principle, and current literature on MOFs-based electronic sensors, such as optical, chemiresistive, and electromechanical sensors in terms of work function of MOFs, futures challenges, as well as prospects outlook. © 2024 WILEY-VCH GmbH. Published 2024 by WILEY-VCH GmbH. All rights reserved.
Heteroleptic 1D coordination polymers: 5-Coordinated zinc(II) polymer as an efficient transesterification catalyst
(Elsevier Ltd, 2017) Manzoor A. Wani; Ashish Kumar; Mrituanjay D. Pandey; Rampal Pandey
The synthesis of three 1D coordination polymers (CPs), [Zn(TPPZ)(HCCB)]n·DMF·H2O (1) [Cd(TPPZ)(HCCB)]n(2) and [Co(TPPZ)(HCCB)]n(3), based on the N,N,N-chelating κ3-2,3,5,6-tetrakis(2-pyridyl)pyrazine (TPPZ) and polymerizing carboxylate (–COO−) 3-(carboxy-methylamino)-4-chlorobenzoic acid (H3CCB) ligands, using a solvothermal method, have been described. The CPs have been adequately characterized by satisfactory elemental analyses, FT-IR, UV–vis, emission, TGA and PXRD analysis. The structure of 1 has been verified by single crystal X-ray diffraction analysis. The structural data revealed the 5-coordinated heteroleptic polymeric framework is exclusively extended through the H3CCB carboxylate group and strong N,N,N-chelating TPPZ ligand acts as a branch terminating site. Notably, the structure of 1 is comprised of one unit of each H2O and DMF solvent in its crystal lattice. In contrast, 2 and 3 exclude lattice solvents, as suggested by PXRD studies, after thermal desolvation of 1. Furthermore, 1 with 5-coordinated Zn(II) centers exhibited an efficient catalytic performance for transesterification reactions, with remarkable stability and good reusability. © 2017 Elsevier Ltd
Hexavalent chromium scavenging performances of one-pot synthesized hydrous cerium-copper-mixed oxide from contaminated water with plausible mechanism
(Taylor and Francis Ltd., 2024) Ayan Ghosh; Sarat Kanrar; Ankur Srivastava; Mrituanjay D. Pandey; Uday Chand Ghosh; Palani Sasikumar
Prolonged use of the chromate [Cr(VI)]-contaminated water originates severe health problems for the public. Thus, the societal urgency is a reusable and cost-effective material for efficient scavenging of Cr(VI) from contaminated industrial wastewater. Aiming this, we had targeted to prepare some cheap and effective materials for scavenging Cr(VI) from the contaminated water. Herein, we report the preparation of hydrous cerium-copper oxide (HCCO) with some tailored compositions and employed toward the abstraction of chromate from water solution. The HCCO (Ce: Cu = 1:4, mole/mole) has shown the highest Cr(VI) scavenging capacity. Experimentally, highest Cr(VI) abstraction efficiency is recorded at pH ~ 3.0 (508.853 mg. g−1 at 303 K). Kinetically, the Cr(VI) scavenging reaction with HCCO surfaces agrees better with the pseudo second-order model (R2 = 0.987) equation and the equilibrium Cr(VI) distribution data explain the Freundlich isotherm model (R2 = 0.998) equation, which anticipates the multi-layered adsorption on heterogeneous sites of the adsorbent. A negative value of the Gibbs free energy change indicates that the Cr(VI) adsorption over HCCO surfaces is spontaneous. The positive enthalpy change indicates the endothermic nature of the said reaction. © 2024 Taylor & Francis Group, LLC.