Uttam Kumar Das

Primary Ammonium Monocarboxylate Synthon in Designing Supramolecular Gels: A New Series of Chiral Low‐Molecular‐Weight Gelators Derived from Simple Organic Salts that are Capable of Generating and Stabilizing Gold Nanoparticles

Chemistry - An Asian Journal (2013)

Uttam Kumar Das Subhabrata Banerjee Parthasarathi Dastidar

Abstract The primary ammonium monocarboxylate (PAM) synthon has been exploited to generate a new series of PAM salts from the free amine of L ‐phenylalanine‐3‐pyridyl amide, ( S )‐2‐amino‐3‐phenyl‐ N ‐(pyridine‐3‐yl)propanamine (designated as “ B ”), and various substituted benzoic acids (designated as “ A(R) ”; R =4‐Me, 4‐Cl, 4‐Br, 4‐NO 2 , 3‐Me, 3‐Cl, 3‐Br, 3‐NO 2 , 2‐Me, 2‐Cl, 2‐Br, 2‐NO 2 ). The 4‐ and 3‐substituted benzoate salts showed moderate‐to‐excellent gelation ability with a number of polar and apolar solvents. The gels were characterized by DSC, rheology, SEM and TEM, FTIR spectroscopy, etc. Structure–property studies based on single‐crystal powder X‐ray diffraction (PXRD) and FTIR data provided insights into the role of the PAM synthon in the formation of the gel networks. Interestingly, some of the gels were capable of forming and stabilizing gold nanoparticles at room temperature without the use of any exogenous reducing agents.

Synthon

Benzoic acid

Amide

Powder Diffraction

10.1002/asia.201300805

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Solvent-regulated fluorescence off–on signaling of Ni(ii) and Zn(ii) with the formation of two mononuclear complexes with an ATP detection ability by Zn(ii) assembly

The Analyst (2022)

Subham Ray Soumik Laha Manik Das Uttam Kumar Das Arijit Bag

The current study shows that Schiff base HL, (Z)-2,4-dibromo-6-(((piperidin-2-ylmethyl)imino)methyl)phenol, can be used successfully as a selective chemosensor for Zn(II) and Ni(II) among several competing cations in purely aqueous and semi-aqueous media. Under UV light in methanol-water (9 : 1) HEPES buffer, the receptor gives its response by changing its color to cyan color in the presence of Zn(II) and to bluish cyan color in the presence of Ni(II). Surprisingly, the chemosensor can only reliably identify Zn(II) in a hundred percent aqueous medium by changing its color to light yellow. UV and fluorescence studies in both aqueous and semi-aqueous media are used to further investigate this Zn(II) and Ni(II) recognition phenomenon. The high values of the host-guest binding constants, obtained by electronic and fluorescence titration, ensure that a strong bond exists between HL and Ni(II)/Zn(II). As anticipated, two highly luminescent mononuclear, crystalline compounds, complexes 1 and 2, have been developed by a separate reaction of HL and Zn(II)/Ni(II), and the high luminous properties are due to the occurrence of Chelation Enhanced Fluorescence (CHEF). According to the single crystal structure, the asymmetric units of both complexes consist of two deprotonated chemosensor units and one Zn(II)/Ni(II), leading to the formation of an octahedral complex. For Ni(II) and Zn(II) sensing, the predicted LOD is in the nanomolar range. Both complexes 1 and 2 are fluorescence active and studies to check their ATP detection ability, but intriguingly, only complex 2 is capable of detecting ATP in a fully aqueous solution. Finally, the live cell imaging study validates the two sensors' biosensing functionality.

10.1039/d2an01938h

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CCDC 937538: Experimental Crystal Structure Determination

The Cambridge Structural Database (2013)

Uttam Kumar Das Parthasarathi Dastidar

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/cc10gl57

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CCDC 957014: Experimental Crystal Structure Determination

The Cambridge Structural Database (2014)

Uttam Kumar Das Rajesh K. Jena Manish Bhattacharjee

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/cc113vff

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CCDC 1409893: Experimental Crystal Structure Determination

The Cambridge Structural Database (2017)

Palash Mondal Sankar Prasad Parua Poulami Pattanayak Uttam Kumar Das Surajit Chattapadhyay

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/ccdc.csd.cc1jb3fd

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Effect of ancillary ligand on DNA and protein interaction of the two Zn (II) and Co (III) complexes: experimental and theoretical study

Journal of Biomolecular Structure and Dynamics (2021)

Manik Das Paula Brandão Soumya Sundar Mati Saikat Roy Anakuthil Anoop

In the present work we have developed one mononuclear Zn(II) complex [Zn(L)(H2O)] (Complex 1) by utilizing a tetracoordinated ligand H2L, formed by simple condensation of 2, 2 dimethyl 1,3 diamino propane and 3- ethoxy salicylaldehyde and one newly designed mononuclear Co (III) complex [Co(L)(L1)] (complex 2) by utilizing (H2L) and 3- ethoxy salicylaldehyde(HL1) as an ancillary ligand. The newly developed complex 2 have been spectroscopically characterized. An interesting phenomenon has been noticed that in presence of ancillary ligand, the solubility in buffer solution and the thermal stability of complex 2 comparatively increases than 1. To check the effect of ancillary ligand, present in complex 2 towards the DNA and HSA binding efficacy, both the complexes have been taken into consideration to inspect their binding potentiality with the macromolecules. The 'on', 'off' fluorescence changes in presence of DNA and HSA, the binding constant values, obtained from electronic spectral titration, iodide induced quenching, competitive binding assay, circular dichroism (CD) spectral titration, time resolved fluorescence experiment unambiguously assure the better binding efficacy of complex 2 with the signal of minor groove binding mode with DNA along with no significant conformational changes of the macromolecules. The strong and spontaneous binding of complex 2 with CT-DNA is further supported by the Isothermal Titration Calorimetry (ITC) study. Furthermore TDDFT calculation of DNA with and without complex 2 significantly authorize the formation of complex 2-DNA adduct during the association. Finally Molecular Docking study properly verifies the experimental findings and provides justified explanation behinds experimental findings.Communicated by Ramaswamy H. Sarma

Isothermal Titration Calorimetry

Binding constant

10.1080/07391102.2021.2001377

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CCDC 1045622: Experimental Crystal Structure Determination

The Cambridge Structural Database (2016)

Madhavi Oruganti Pavan A. Khade Uttam Kumar Das Darshak R. Trivedi

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/cc1431r1

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CCDC 937835: Experimental Crystal Structure Determination

The Cambridge Structural Database (2013)

Jérôme Bayardon H. Laureano Vincent Diemer Mathieu Dutartre Uttam Kumar Das

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/cc10gwr3

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CCDC 926439: Experimental Crystal Structure Determination

The Cambridge Structural Database (2016)

Uttam Kumar Das Subhabrata Banerjee Parthasarathi Dastidar

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Crystal (programming language)

10.5517/cc103149

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CCDC 1878333: Experimental Crystal Structure Determination

The Cambridge Structural Database (2019)

Uttam Kumar Das Yehoshoa Ben‐David Gregory Leitus Yael Diskin‐Posner David Milstein

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

10.5517/ccdc.csd.cc211kd2

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Uttam Kumar Das

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