Publications by authors named "Subhendu Mondal"

To develop fluorophore-labelled pyridinium-based macromolecular architectures for fluorometric and colorimetric detection of anions, two polymers P1 and P2 are synthesized. Linear polymer P1 and cross-linked polymer P2, prepared from N-methacryloyl-3-aminopyridine monomers via free radical polymerization followed by quaternization of the pyridine ring nitrogen with anthracene as a fluorescent marker, have been successfully employed in anion sensing. P1 exhibits excellent sensing of HPPi in aqueous DMSO.

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2,6-Diaminopyridine-coupled rhodamines and have been synthesized, and the effect of substitution on amine functionality toward metal-ion interactions and self-assembly is thoroughly investigated. Both the compounds effectively recognize different metal ions of biological significance fluorimetrically and colorimetrically with a high degree of selectivity and sensitivities. While compound is sensitive to Fe ions, compound is responsive to both Fe and Al ions in aqueous CHCN (4/1, v/v; 10 mM tris HCl buffer, pH 6.

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Article Synopsis
  • The study focuses on improving methods to reconstruct the structure of nanoscale samples using coherent diffractive imaging with X-ray free-electron lasers, even when the quality of the diffraction data is low.
  • A new refinement method is introduced that uses a gradient search technique, which takes into account gaps in the diffraction patterns and limited photon detection, enhancing convergence by starting with an initial structure estimate.
  • The method was successfully applied to experimental data from an Xe cluster at the SACLA facility, demonstrating effective reconstruction of electron density from challenging diffraction patterns, thereby aiding in the analysis of samples with low scattering power.
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The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in real-time. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser.

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We show that electron and ion spectroscopy reveals the details of the oligomer formation in Ar clusters exposed to an x-ray free electron laser (XFEL) pulse, i.e., chemical dynamics triggered by x rays.

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α-Amino acid derived benzimidazole-linked rhodamines have been synthesized, and their metal ion sensing properties have been evaluated. Experimentally, l-valine- and l-phenylglycine-derived benzimidazole-based rhodamines 1 and 2 selectively recognize Al ion in aqueous CHCN (CHCN/HO 4/1 v/v, 10 mM tris HCl buffer, pH 7.0) over the other cations by exhibiting color and "turn-on" emission changes.

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In recent years, free-electron lasers operating in the true X-ray regime have opened up access to the femtosecond-scale dynamics induced by deep inner-shell ionization. We have investigated charge creation and transfer dynamics in the context of molecular Coulomb explosion of a single molecule, exposed to sequential deep inner-shell ionization within an ultrashort (10 fs) X-ray pulse. The target molecule was CH3I, methane sensitized to X-rays by halogenization with a heavy element, iodine.

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Article Synopsis
  • * The experiments involved using momentum-resolved techniques to track electron and ion interactions following these excitations in argon.
  • * Our findings show that ICD triggered by resonant Auger decay is an effective method for generating slow electrons with specific energy levels at targeted locations.
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