Browsing by Author "B. Maiti"

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Ag(i), Cu(II), Co(III) and Hg(II) complexes and metal-assisted products derived from 4-methyl-piperidine-carbodithioate: Syntheses, structures, thermal analyses, redox behaviour and fluorescence properties
(Royal Society of Chemistry, 2016) Paras Nath; M.K. Bharty; B. Maiti; A. Bharti; R.J. Butcher; J.L. Wikaira; N.K. Singh
Four new complexes [Ag2(4-mpipdtc)2(PPh3)2] (1), [Cu(4-mpipdtc)2] (2), [Co(4-mpipdtc)3]·CHCl3 (3) and [PhHg(4-mpipdtc)] (4) and two new products, bis(4-methyl piperidinethiocarbonyl) disulfide {(4-mpipdtc)2} (5) and (4-methyl-piperidin-1-yl) carbothioylsulfanyl-methyl (4-methyl)-piperidine-1-carbodithioate {CH2(4-mpipdtc)2} (6) have been obtained in this study. The syntheses of compounds 5 and 6 were assisted by Mn(ii) and Ag(i) ions, respectively, and were obtained from potassium 4-methyl-piperidine-carbodithioate {K+(4-mpipdtc)-} {where, 4-mpipdtc- = 4-methyl piperidine carbodithioate}. All new compounds have been characterized by elemental analyses, IR, NMR, magnetic susceptibility and single X-ray crystallography techniques. These compounds are stabilized by intermolecular C-H⋯S, S⋯S, C-H⋯π and C-H⋯N interactions. The most interesting feature in complex 4 is that the ligand bound phenylmercury cation is stabilized via intermolecular as well as intramolecular Hg⋯S secondary interactions. Compounds 3 and 5 are highly fluorescent in a solution when compared to the free ligand and emit violet/violet-blue light at 372 and 413 nm upon excitation at 328 and 300 nm, respectively. The course of the thermal degradation of complexes 1-4 have been investigated by TG-DTA, which indicates that metal sulphide is formed as the final residue. The results obtained from the electronic structure calculations at the density functional theory level corroborate our experimental findings obtained from the IR data. Frontier molecular orbital analysis reveals that complexes 1 and 3 are softer and more reactive than complexes 2 and 4. Cyclic voltammetry shows that complex 2 exhibits a reversible Cu(ii)/Cu(i) redox process at 0.515 V, whereas the ligand and complexes 1, 3 and 4 show irreversible redox behaviour. © The Royal Society of Chemistry 2016.
Electrochemical and quantum chemical studies of 3,4-dihydropyrimidin-2(1H)-ones as corrosion inhibitors for mild steel in hydrochloric acid solution
(2010) Dileep Kumar Yadav; B. Maiti; M.A. Quraishi
The inhibition effect of 3,4-dihydropyrimidin-2(1H)-ones (DHPMs) on the corrosion of mild steel in hydrochloric acid medium has been investigated using weight loss measurements, electrochemical impedance spectroscopy, potentiodynamic polarization and quantum chemical study. Among the compounds studied, DHPM-3 exhibited the best inhibition efficiency η (%) 99% at 10mgL-1 at 308K. Polarization measurements indicate that all the examined compounds are of mixed-type inhibitor. The adsorption of studied compounds obeyed the Langmuir's adsorption isotherm. The electronic properties obtained using quantum chemical approach, were correlated with the experimental inhibition efficiencies. © 2010 Elsevier Ltd.
In vitro and In silico anticancer activities of Mn(ii), Co(ii), and Ni(ii) complexes: synthesis, characterization, crystal structures, and DFT studies
(Royal Society of Chemistry, 2022) M.K. Gond; Shivendra Kumar Pandey; R. Singh; Manoj K. Bharty; Partha Pratim Manna; V.K. Singh; B. Maiti; L.B. Prasad; R.J. Butcher
The development of a potent metallodrug to prevent the progression of cancer is needed urgently. Here, three new complexes [Mn(pfth)2(o-phen)] (1), [Co(pfth)2(en)] (2) and [Ni(pfth)2(en)] (3) based on a 4-phenyl-(2-furoyl)-thiosemicarbazide (Hpfth) ligand containing 1,10 phenanthroline (o-phen)/ethylenediamine (en) as secondary ligands have been synthesized. The synthesized complexes have been characterized by various analytical, spectroscopic (IR, UV-vis., NMR), and single-crystal X-ray diffraction techniques. The results obtained by quantum chemical calculations (DFT and TD-DFT) agree with the experimentally observed values. The tumoricidal potential of Mn, Co, and Ni salts, ligand Hpfth, and their coordinate complexes was evaluated against K562, MCF-7, and DL cancer cell lines. Both short-term (XTT and MTT assays) and long-term (clonogenic assay) treatment of the tumor cells studied through colorimetric, clonogenic, and fluorescence-based assays by the complexes demonstrated true anti-tumor effects against these cancer cells. The results suggest the significant antitumor potential of the metal-ligand complexes against the tumor cells in a dose-dependent manner with higher growth inhibition, apoptosis, and inhibition in colony formation in comparison to either metal salts or free ligands. Complexes 1 and 3 induce more growth inhibition as compared to complex 2 against all cancer cell lines. Complex 3 demonstrated impressive tumoricidal properties in a clonogenic assay in comparison to complexes 1 and 2. These studies establish the role of metal centers in antiproliferative activities and reveal that Ni(ii) exhibits more potent anti-tumoricidal activity. Molecular docking studies of Hpfth and complexes 1-3 were also performed against three target proteins 6NE5: Myeloid Cell Leukemia-1 (Mcl-1), 6E91: Carbonic anhydrase IX (CA IX), and 6H0W: Lysine Demethylase 4D and the results displayed favorable binding interactions. © 2022 The Royal Society of Chemistry
Inhibition effect of some benzylidenes on mild steel in 1M HCl: An experimental and theoretical correlation
(2012) Dileep Kumar Yadav; M.A. Quraishi; B. Maiti
The inhibition performance of four benzylidine malononitriles (BMNs) on mild steel (MS) in 1M HCl was studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The associated activation energy (E a) and free energy of adsorption (ΔGads°) have been determined. The adsorption of inhibitors on MS surface obeyed the Langmuir's adsorption isotherm. Potentiodynamic polarization measurements showed that all inhibitors are mixed type. The energy dispersive X-ray (EDX) and scanning electron microscope (SEM) observations confirmed the existence of a protective film of inhibitor on MS surface. The results of the quantum chemical calculations were correlated with experimental inhibition efficiencies. © 2011 Elsevier Ltd.
Manganese(II) catalyzed synthesis of bis(N-cyclohexylthiourea) derived from thiosemicarbazide: Structural characterization, fluorescence, cyclic voltammetry, Hirshfeld surface analysis and DFT calculation
(Elsevier B.V., 2021) S. Jaiswal; M.K. Gond; M.K. Bharty; B. Maiti; S. Krishnamoorthi; R.J. Butcher
A new compound bis(N-cyclohexylthiourea) (H2chth) has been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray diffraction data. Compound H2chth crystallizes in triclinic system with space group P-1. During the course of reaction, the cyclohexyl isothiocynate moiety of the substituted thiosemicarbazide undergoes tautomerization and rearrangement into the corresponding carbothioamide moiety in the presence of manganese(II) acetate. The interaction of H2chth with different metal ions in methanol solution is studied and it shows interesting red shifts with Mn2+, Co2+, Ni2+, Cu2+, Zn2+ and Cd2+ ions which suggests that compound H2chth may be a useful probe for sensing of these metal ions. Cyclic voltammetric studies of H2chth and its interaction with different metal ions exhibit complete irreversible redox behavior. Compound H2chth exhibits emission at 27322 cm−1 upon excitation at 37037 cm−1. The emission spectra of different metal ions with H2chth exhibit less intense emissions as compared to the free H2chth. The structure of compound H2chth is stabilized via intermolecular N-H···S and C-H···S hydrogen bonding. The geometry of the compound H2chth has been optimized using the B3LYP density functional theory method and the results are compared with the X-ray diffraction data. The calculated geometrical parameters corroborate with the experimental data. Frontier molecular orbital analysis suggests that compound H2chth is soft and highly reactive. Hirshfeld surface map and 2D finger print plot were used to explore the intermolecular interactions of H2chth. © 2021 Elsevier B.V.
Mn(II) catalyzed synthesis of 5(4-hydroxyphenyl)-2-(N-phenylamino)-1,3,4-oxadiazole: Crystal structure, DFT, molecular docking, Hirshfeld surface analysis, and in vitro anticancer activity on DL cells
(Elsevier B.V., 2022) M.K. Gond; Alok Shukla; Shivendra Kumar Pandey; M.K. Bharty; B. Maiti; A. Acharya; N. Tiwari; D. Katiyar; R.J. Butcher
The syntheses and screening of novel synthetic molecules have gained attention as a potential therapeutic agent in the treatment of cancer. In the present study, a new compound 5(4-hydroxyphenyl)-2-(N-phenylamino)-1,3,4-oxadiazole (Hppo) has been synthesized and its anticancer activity is investigated against Dalton's lymphoma (DL) tumor cells derived from murine T-cell lymphoma. The Hppo has been characterized through IR, NMR, and single-crystal X-ray data. The structure of Hppo is stabilized via hydrogen bonding interactions and crystallizes in an orthorhombic system with space group P b c n. The fingerprint plots associated with Hirshfeld surface analysis indicate that there are different types of weak interactions viz. C-H···N, O-H···N and C-H···O. The DFT calculations are also performed to verify physiochemical properties of Hppo and the results obtained are in good agreement with the experimental results. The HOMO and LUMO energy gap of 7.344 eV for Hppo indicates good NLO properties. The cytotoxicity activity of Hppo is tested against Dalton's lymphoma cells using MTT assay which reveals that the compound showed admirable anticancer activity (IC50= 50 µg/mL), which is better than many previously reported compounds. The mechanism of action of Hppo is investigated by performing different biological studies and the results obtained reveal that Hppo acts through down-regulating mitochondrial membrane potential and up-regulating reactive oxygen species production. Molecular docking studies are also performed to obtain more insights on biological activities of Hppo and its mode of action against CYP-19 (PDB: 3EQM), JAK2 (PDB: 5AEP), BCL-2 (PDB: 2O2F), and caspase3 (PDB: 1RE1), and result displayed favorable binding interactions with binding energy -7.43, -7.96, -6.61, and -6.88 Kcal/mol. © 2021 Elsevier B.V.
Photophysical, electrochemical and TD-DFT studies of Ni(II) and Mn(II) complexes of N′-(2-methylfuran-3-carbonyl)hydrazine carbodithioic acid ethyl ester
(Elsevier Ltd, 2019) R. Chaurasia; M.K. Bharty; Paras Nath; Piyush Kumar Sonkar; Vellaichamy Ganesan; B. Maiti; A. Bharti; R.J. Butcher
Two new complexes [Ni(Hmfchce)2(py)2] (1) and [Mn(Hmfchce)2(o-phen)] (2) with [N′-(2-methylfuran-3-carbonyl)hydrazine]-carbodithioic acid ethyl ester (H2mfchce) have been synthesized which contain o-phenanthroline (o-phen)/pyridine (py) as coligand. The ligand and its metal complexes have been characterized by elemental analyses, IR, magnetic susceptibility and single crystal X-ray diffraction data. Complexes 1 and 2 crystallize in orthorhombhic system with space group ‘Pbca’ and ‘Pbcn’, respectively. In complex 1, nickel centre is coordinated through one hydrazine nitrogen atom, one carbonyl oxygen of two units of ligand and two pyridine nitrogen atoms. The manganese center in complex 2 is coordinated in a N4O2 core by two uininegative bidentate ligands using hydrazine nitrogen (after loss of proton) and carbonyl oxygen and two nitrogen atoms of o-phen. In both complexes, the metal ion adopts a distorted octahedral geometry. Complexes 1 and 2 are fluorescent materials which exhibit an emission at 291 and 285 nm, respectively upon excitation at 263 and 251 nm. The course of the thermal degradations of complexes 1 and 2 have been investigated by TGA which indicate that metal oxide is formed as the final residue in both complexes. The metal complexes, [Ni(Hmfchce)2(py)2] (1) and [Mn(Hmfchce)2(o-phen)] (2) were immobilized on glassy carbon electrodes using Nafion® (Nf). The modified electrodes have been characterized by cyclic voltammetry in 0.1 M KOH. Complexes 1 and 2 have efficient activity towards electrochemical water oxidation in the 0.1 M KOH. The simulated spectra of the two complexes 1 and 2 are characterized by excited states with ligand-to-ligand charge-transfer (LLCT) and ligand-to-metal charge-transfer (LMCT) character. © 2019 Elsevier Ltd
Square planar Ni(II) complexes of pyridine-4-carbonyl-hydrazine carbodithioate, 1-phenyl-3-pyridin-2-yl-isothiourea and 4-(2-methoxyphenyl) piperazine-1-carbodithioate involving N-S bonding: An approach to DFT calculation and thermal studies
(Elsevier Ltd, 2013) P. Bharati; A. Bharti; M.K. Bharty; B. Maiti; R.J. Butcher; N.K. Singh
Three new complexes [H2en][Ni(pchc)2] (1) (pchc = pyridine-4-carbonyl-hydrazine carbodithioate), [Ni(Hppith)2] (2) (H2ppith = 1-phenyl-3-pyridin-2-yl-isothiourea) and [Ni(mppcdt) 2] (3) {mppcdt = 4-(2-methoxyphenyl)piperazine-1-carbodithioate} have been synthesized and characterized by elemental analyses, IR and single crystal X-ray diffraction data. The ligand H2ppith and complexes [H 2en][Ni(pchc)2] (1) [Ni(Hppith)2] (2) and [Ni(mppcdt)2] (3) crystallize in monoclinic, orthorhombic, monoclinic and triclinic system with space group P21/n, Icab, C2/c and P1, respectively. The nitrogen and sulfur donor sites of the bidentate ligands chelate Ni(II) forming two five-membered CSN2M chelate rings in the complex 1, two six membered C2SN2M rings in complex 2 and the sulfur donor sites of the bidentate ligand chelate Ni(II) forming two four membered CS2M rings in complex 3. The Ni(II) complexes are diamagnetic and have distorted square planar geometry. The crystal structure of the complexes are stabilized by various types of inter and intramolecular extended hydrogen bonding providing supramolecular framework. Results obtained from quantum chemical calculations at the density functional theory level corroborate our experimental findings from IR and UV. The course of the thermal degradation of complexes 1,2 and 3 has been investigated by TG-DTA. Thermogravimetric analyses of the complexes indicate NIO/NIS as the end residue. © 2013 Elsevier Ltd. All rights reserved.
Synthesis, spectral, structural, photoluminescence, thermal and DFT studies of phenylmercury(II) and Ni(II) complexes of 3-methoxycarbonyl-piperidine-1-carbodithioate
(Elsevier Ltd, 2018) Paras Nath; M.K. Bharty; S.K. Kushawaha; B. Maiti
Two new complexes [PhHg(mpc)] (1) and [Ni(mpc)2] (2) {mpc = 3-methoxycarbonyl-piperidine-1-carbodithioate} have been synthesized and characterized by elemental analyses, IR, NMR, UV–Vis and single crystal X-ray diffraction data. Both the complexes crystallize in triclinic system with space group P1¯. The geometry around the Hg(II) ion bonded with phenyl carbon and dithiosulfur atom of mpc is almost linear. Complex 2 is square planar having two unit of mpc ligand. Potassium salt of mpc and complex 1 emit violet light upon excitation at about 293 nm, while complex 2 emit blue light upon excitation at 323 nm wavelength. Cyclic voltammetry studies of free ligand (Kmpc) and its complexes 1 and 2 shows irreversible redox behaviour. Thermal behaviour of the complexes 1 and 2 have been studied which indicate that complex 1 evaporates completely over 700 °C temperature where as complex 2 converts into nickel sulfide as final residue. Frontier molecular orbital analysis reveals that complex 2 is softer and more reactive than complex 1. In the solid state, crystal structures of complexes are stabilized by intermolecular interactions. © 2018 Elsevier Ltd
Synthesis, structural characterization, DFT, fluorescence, and redox behaviour of 4-[5-(2-picolylsulfanyl)-1,3,4-oxadiazole-2-yl]-pyridine
(Elsevier B.V., 2022) S. Chandra; M.K. Gond; S. Jaiswal; M.K. Bharty; B. Maiti; D. Kushwaha; R.J. Butcher
The effective experimental content of this paper reports the synthesis of new 1,3,4-oxadiazole derivative 4-[5-(2-picolylsulfanyl)-1,3,4-oxadiazole-2-yl]-pyridine (pop) which was carried out in a cyclization reaction containing potassium N′-(pyridine-4-carbonyl)-hydrazinecarbodithioate in the presence of 2-picolyl chloride. The synthesized compound pop has been characterized by elemental analyses, UV–vis., Infrared, NMR, and X-ray diffraction data which crystallizes in a triclinic system having space group P-1. The dihedral angle formed between the pyridine ring and oxadiazole ring indicates that all the rings present in the compound are planar with each other. An electrochemical study shows that compound pop exhibits a reversible redox process assignable to a one-electron transfer reaction. The intermolecular C–H···N hydrogen bonding and π···π interactions provide stability to the structure of compound pop. The fingerprint plots associated with Hirshfeld surface analysis clearly shows that there are two types of weak interactions N···H–C and S···C through red spots. Fluorescence spectra of Co2+, Cr2+, Cu2+, Cd2+, Hg2+, and Zn2+ ions with pop exhibit better fluorescence whereas Mn2+ and Ni2+ ions are less fluorescent as compared to the free pop. To get a better understanding of Frontier molecular orbitals and intramolecular charge transfer property, theoretical calculations, such as density functional theory (DFT), were performed which indicates that compound pop is soft and highly reactive. © 2021
Synthesis, structural characterization, electrochemical studies and DFT calculations on nickel(II) complexes of N-picolinoyl-N′-benzothioylhydrazide and 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione
(Springer International Publishing, 2017) M.K. Bharty; S.K. Kushawaha; U.K. Chaudhari; R.K. Dani; B. Maiti; R.J. Butcher
Two Ni(II) complexes, [Ni(pbth)2] and [Ni(ptt)2(en)2] {Hpbth = N-picolinoyl-N′-benzothioylhydrazide, Hptt = 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione} have been synthesized and characterized by physico-chemical and spectroscopic methods. [Ni(pbth)2] contains a pair of N-picolinoyl-N′-benzothioylhydrazide ligands coordinated via their thione sulfur, pyridyl nitrogen and hydrazinic nitrogen atoms, forming two C2N2Ni and two CSN2Ni five-membered chelate rings. The intermediate compound 1-isonicotinoyl-3-thiosemicarbazide is converted to 5-(pyridine-4-yl)-2H-1,2,4-triazole-3-thione in the presence of ethanolic NaOH, giving the complex [Ni(ptt)2(en)2] in which the ptt ligands coordinate through their triazole ring nitrogen atoms, while four more nitrogens from two ethylenediamine ligands complete the octahedral structure. The crystal structures of the complexes involve various types of intermolecular extended hydrogen bonds, forming supramolecular frameworks. Cyclic voltammetry studies of both complexes show quasi-reversible redox behavior. Density Functional Theory electronic structure calculations corroborate our experimental findings. © 2017, Springer International Publishing Switzerland.
Zinc(II) catalyzed synthesis of 2-(4-methoxyphenyl)-5-(2-pyridyl)-1,3,4-thiadiazole: Characterizations, crystal structure, DFT calculation, Hirshfeld surface analysis, and molecular docking analysis
(Elsevier B.V., 2022) M.K. Gond; Shivendra Kumar Pandey; S. Chandra; N. Tiwari; M.K. Bharty; B. Maiti; D. Katiyar; R.J. Butcher
A new compound 2-(4-methoxyphenyl)-5-(2-pyridyl)-1,3,4-thiadiazole (Mppth) has been synthesized and characterized with the aid of IR, NMR, and single-crystal X-ray diffraction techniques. During the reaction, the substituted thiohydrazide got cyclized into the corresponding thiadiazole (Mppth) in the presence of zinc(II) nitrate via loss of H2O. The Mppth crystallizes in an orthorhombic system with space group P 21 21 21. The solid-state structure of Mppth is stabilized via intermolecular hydrogen bonding and π-π interaction between phenyl rings. The intermolecular interactions present in the crystal structure of Mppth are also confirmed with Hirshfeld surface analysis. The geometry optimization has been performed using the DFT method and geometrical parameters thus obtained for the Mppth correlate with the single-crystal X-ray data. The FMO analysis shows a small HOMO and LUMO energy gap of 5.48 eV for Mppth suggesting its potential application as NLO material. The electronic transition from the ground state to the excited state due to a transfer of electrons from the HOMO to LUMO levels is mainly associated with the π→π* transition. Molecular docking studies are also performed against CYP-19 (PDB: 3EQM), JAK2 (PDB: 5AEP), BCL-2 (PDB: 2O2F), and caspase3 (PDB: 1RE1) receptor proteins to obtain insights on anticancer activities of Mppth. The results displayed strong interactions with the receptors with binding energies -10.27, -7.40, -6.28, and -7.27 kcal/mol, respectively. From the docking results, the key binding interactions between the ligand and active site residues of the receptor were identified, which may provide important information for further research on the compound Mppth as anticancer agent. © 2022