Browsing by Author "Mondal B."

Now showing 1 - 3 of 3
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    A and B site engineered doping of the Bi2O3 to tune the structural and optical properties of lead-free BCZT ceramic
    (Elsevier Ltd, 2024) Mondal B.; Seth S.; Pal S.P.
    This work reports the different solid-state synthesis routes to tune between the A-site and B-site incorporation of the Bi2O3 additive element in the lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramic. The structural and optical properties of the synthesized samples were systematically investigated by utilizing XRD, FT-IR spectroscopy, Raman Spectroscopy, UV�visible, and Photoluminescence spectroscopy. The shifting of the XRD peaks towards higher angles and the decrement of the O�Ba�O bond length in the FT-IR spectra of the doped sample confirmed the A-site incorporation of the Bi3+ ion. Whereas, B-site substituted samples have shown the lower angle shifting of the XRD peaks and increased value of the O�Ti�O bond length in FT-IR spectra. The presence of co-existing multi-phases in all prepared ceramics structures were verified by the splitting of XRD peaks and Raman Spectroscopy data analysis. A significant decrement in the value of the energy band gap and higher emission intensity for the A-site doped sample was observed from the UV�visible and PL spectra respectively. These observations made from the optical properties indicate that the A-site substituted ceramics can greatly enhance the electrical and optical properties of the pure material concerning the B-site substituted ceramics. � 2023 Elsevier B.V.
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    Dinuclear platinum(ii) complexes with biphenyl-based bis-carbene ligands
    (Royal Society of Chemistry, 2024) Naskar R.; Mondal B.; Sengupta D.; Ghosh A.; Garai S.; Maity R.
    Multimetallic NHC (N-heterocyclic carbene) complexes comprising platinum(ii) centers are rare. Four new dinuclear platinum(ii) complexes possessing a combination of NHC and Py/4-Cl(Py) ligands are presented. Both classical and mesoionic carbene (MIC) ligands have been employed for the complexation. All complexes have been characterized using standard spectroscopic tools. The coordination of both classical NHC and pyridine ligands around the platinum(ii) center in complex [2] has been established by using single crystal XRD. � 2024 The Royal Society of Chemistry.
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    Tetranuclear PdII Complexes Containing an Adamantane-Based Tetra-MIC Ligand: Ancillary-Ligand-Dependent Catalytic and Redox Activities
    (American Chemical Society, 2024) Mondal B.; Naskar R.; Bag J.; Garai S.; Maity R.
    The novel tetra-triazolium salt 1, featuring a tetrasubstituted central adamantane backbone, is introduced for the synthesis of tetranuclear PdII MIC complexes by quadruple C5-H deprotonation and subsequent addition of the corresponding PdII precursors. The three newly prepared palladium(II) complexes appeared to be stable and have been characterized using standard spectroscopic and HRMS techniques. The molecular structure of the tetranuclear PdII complex bearing a 4-methoxypyridine ligand has been established by using single-crystal XRD. All three newly prepared tetranuclear PdII complexes appeared as active precatalysts for the Sonogashira coupling reaction, which occurred in a homogeneous fashion; however, only the palladium(II) complex bearing a combination of MIC and phosphine ligands was found to be active for the intermolecular ?-arylation of 1-methyl-2-oxindole, as the complexes bearing a pyridine or a 4-methoxypyridine ligand decomposed to Pd0 NPs and appeared to be inactive in the ?-arylation reaction. The ancillary-ligand-dependent (Py vs PPh3) interplay between homogeneous and heterogeneous catalyses has also been correlated with the catalytic outcomes in ?-arylation of 1-methyl-2-oxindole. The electrochemical responses of these complexes have been measured, and the effect of ancillary ligands in both electrochemistry and catalysis has also been examined. � 2024 American Chemical Society.