Kishalay Bhar

Bio: Kishalay Bhar is an academic researcher from Central University of Rajasthan. The author has contributed to research in topics: Schiff base & Octahedral molecular geometry. The author has an hindex of 15, co-authored 58 publications receiving 643 citations. Previous affiliations of Kishalay Bhar include University of Burdwan.

Crystallographic Evidence for Reversible Symmetry Breaking in a Spin‐Crossover d7 Cobalt(II) Coordination Polymer

Abstract: This work was supported by the DST and CSIR, India. J.S.C. thanks the Spanish MICINN through CTQ2009-06959 for the research fellowship “Juan de la Cierva” (18-08-463B-750). J.R. also thanks the Spanish MICINN through CTQ2009-07264.

Design, synthesis, characterization and evaluation of the anticancer activity of water-soluble half-sandwich ruthenium(II) arene halido complexes

Abstract: The synthesis, detailed characterization, and investigation of the DNA- and BSA-binding affinity and cytotoxicity of three half-sandwich Ru(II) arene chlorido complexes (1–3) are reported. Specifically, organometallic complexes [(η6-p-cymene)(L1)RuCl]Cl (1), [(η6-p-cymene)(L2)RuCl]Cl (2) and [(η6-p-cymene)(L3)RuCl]Cl (3) [L1 = 2-(1H-benzo[d]imidazol-2-yl)quinolone, L2 = 2-(quinolin-2-yl)benzo[d]oxazole, and L3 = 2-(quinolin-2-yl)benzo[d]thiazole] were synthesized using [((η6-p-cymene)Ru(μ-Cl)Cl)2] and L1–L3. All the complexes were characterized by various spectroscopic and analytical methods. Complex 1 was also characterized by single crystal X-ray diffraction analysis, the results of which are in-line with the piano-stool structure elucidated from the spectroscopic methods. Cyclic voltammetry of 1–3 showed good stability of the Ru(II) state. The interactions of 1–3 with CT-DNA were investigated by UV-Vis studies and competitive binding with ethidium bromide (EthBr) using emission spectroscopy. Steady-state fluorescence quenching and synchronous fluorescence studies were performed to understand the interactions between 1–3 and bovine serum albumin (BSA). The geometry optimization of 1–3 was performed using the density functional theory (DFT). Complexes 1 and 2 were investigated for DNA binding using theoretical calculations. Molecule complexes 1-DNA and 2-DNA were huge (482–483 atoms, 2442 electrons) for any level of quantum chemical analysis. The semi-empirical PM6 method, which is more accurate than the force-field methods, was used, and the result suggested that several strong and weak electrostatic and intermolecular hydrogen bonding interactions exist between the outer edge of DNA and complexes 1 and 2. In addition, the in vitro cytotoxicity of L1–L3 and complexes 1–3 against a breast cancer cell line (MCF-7) was investigated by MTT cytotoxicity analyses. The studies performed here show that these complexes exhibit a good binding behavior with DNA and BSA and show good anticancer potency towards MCF-7 cells.

Spin state switching in iron coordination compounds

Abstract: The article deals with coordination compounds of iron(II) that may exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their detection and characterization. Spin crossover compounds, though known for more than eight decades, have become most attractive in recent years and are extensively studied by chemists and physicists. The switching properties make such materials potential candidates for practical applications in thermal and pressure sensors as well as optical devices. The article begins with a brief description of the principle of molecular spin state switching using simple concepts of ligand field theory. Conditions to be fulfilled in order to observe spin crossover will be explained and general remarks regarding the chemical nature that is important for the occurrence of spin crossover will be made. A subsequent section describes the molecular consequences of spin crossover and the variety of physical techniques usually applied for their characterization. The effects of light irradiation (LIESST) and application of pressure are subjects of two separate sections. The major part of this account concentrates on selected spin crossover compounds of iron(II), with particular emphasis on the chemical and physical influences on the spin crossover behavior. The vast variety of compounds exhibiting this fascinating switching phenomenon encompasses mono-, oligoand polynuclear iron(II) complexes and cages, polymeric 1D, 2D and 3D systems, nanomaterials, and polyfunctional materials that combine spin crossover with another physical or chemical property.

Mushroom-Derived Carbon Dots for Toxic Metal Ion Detection and as Antibacterial and Anticancer Agents

Abstract: Although carbon nanoparticles or quantum dots (C-dots) have been studied extensively for a variety of applications (e.g., photocatalysis, metal ion sensing, antibacterial, cell labeling), a greener...