Tapas Kumar Raychaudhuri

Bio: Tapas Kumar Raychaudhuri is an academic researcher from University of Calcutta. The author has contributed to research in topics: Denticity & Ligand. The author has an hindex of 7, co-authored 9 publications receiving 136 citations.

Chemical, electrochemical and structural studies of some cis -dioxomolybdenum(VI) complexes of two tridentate ONS chelating ligands

Abstract: Several cis-dioxomolybdenum complexes of two tridentate ONS chelating ligands H2L1 and H2L2 (obtained by condensation of S-benzyl and S-methyl dithiocarbazates with 2-hydroxyacetophenone) have been prepared and characterized. Complexes 1 and 2 are found to be of the form MoO2 (CH3OH) L1 · CH3OH and MoO2L, respectively, (where L2– = dianion of H2L1 and H2L2). The sixth coordination site of the complexes acts as a binding site for various neutral monodentate Lewis bases, B, forming complexes 3–10 of the type MoO2LB (where B = γ-picoline, imidazole, thiophene, THF). The complexes were characterized by elemental analyses, various spectroscopic techniques, (UV-Vis, IR and 1H NMR), measurement of magnetic susceptibility at room temperature, molar conductivity in solution and by cyclic voltammetry. Two of the complexes MoO2(CH3OH) L1 · CH3OH (1) and MoO2L1(imz) (5) were structurally characterized by single crystal X-ray diffraction. Oxo abstruction reactions of 1 and 5 led to formation of oxomolybdenum(IV) compl...

Synthesis, chemical, and electrochemical studies of oxomolybdenum(IV) complexes with two tridentate ONS donor ligands

Abstract: This manuscript reports the synthesis, characterization, chemical, and electrochemical studies of several oxomolybdenum (IV) complexes of tridentate ONS donor ligands obtained by the condensation of 2-hydroxyacetophenone with S-benzyl and S-methyl dithiocarbazates. The complexes are of the forms [MoIVOL] and [MoIVOL(N–N)], where N–N = 2,2′-bipyridine and 1,10-phenanthroline, derived from the corresponding [MoO2L] complexes through oxo abstraction by triphenylphosphine in the absence/presence of N–N bidentate donors. Electrochemical behavior of these complexes have been investigated for insight into the redox behavior of the Mo(IV) centers of these complexes.

Thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/ hydrazones: Anti - Mycobacterium tuberculosis activity and cytotoxicity

Abstract: The aim of this study was to identify a candidate drug for the development of anti-tuberculosis therapy from previously synthesized compounds based on the thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/hydrazones compounds. The minimal inhibitory concentration (MIC) of these compounds against Mycobacterium tuberculosis was determined. Their in vitro cytotoxicity to J774 cells (IC50) was determined to establish a selectivity index (SI) (SI=IC50/MIC). The best compounds were the thiosemicarbazones (2, 3 and 4) and the hydrazide/hydrazones (14, 15, 16 and 18). The results are comparable to or better than those of "first line" or "second line" drugs commonly used to treat TB, suggesting these compounds as anti-TB drug candidates.

Transition metal complexes of symmetrical and asymmetrical Schiff bases as antibacterial, antifungal, antioxidant, and anticancer agents: progress and prospects

Abstract: Abstract The huge research on Schiff base coordination complexes in the past few decades has given rise to several new molecules that have been of biological importance. The ease with which the Schiff base ligands are designed and prepared and their pattern is elucidated have made them to be referred to as “fortunate ligands” possessing azomethine derivatives, the C=N linkage that is essential for biological activity, including antibacterial, antifungal, antioxidant, anticancer, and diuretic activities. A variety of Schiff base and its complexes have been studied as model molecules for biological oxygen carrier systems. The uses of Schiff bases as DNA-cleaving agents and its mode of interaction and free-radical scavenging properties are described. The review encapsulates the applications of Schiff bases and their complexes.