Elucidation of efficient dual performance in photodegradation and antibacterial activity by a promising candidate Ni-doped MoO3 nanostructure

Journal of Sol-Gel Science and Technology - In the present work, Nickel doped Molybdenum trioxide (NixMoO3) where Ni = X (X = 5, 10, and 15%) nanoparticles (NPs) were...     

DFT analysis: Fe4 cluster and Fe(110) surface interaction studies with pyrrole,furan, thiophene,and selenophene molecules

DFT studies of both the Fe₄ cluster and the Fe(110) surface interaction with pyrrole, furan, thiophene, and selenophene showed that selenophene forms a stabler adsorbate iron complex than the other heterocyclic molecules; this is consistent with the binding energy data that were calculated between the Fe cluster and the Fe(110) surface with the heterocycles. Furthermore, when the adsorption of the compounds with the iron cluster was analyzed by molecular orbital studies, the orbitals of selenophene overlapped more strongly with the Fe atom than that of the other molecules. In TD-DFT, the π → π* peak observed for the molecules disappeared when they formed complexes, and there appeared a charge transfer band (ligand to metal), thus confirming the coordination of these molecules with the cluster. The data suggest that the chemisorption is an exothermic process.     

Synthesis, Raman, X-ray diffraction, and density functional studies of antimony(III) heterotetracycles displaying intramolecular transannular interactions O → Sb

A set of compounds of general formula [{S(C₆H₃S)₂O}SbHal] [Hal = Cl (1), Br (2), I (3)] has been synthesized and studied by Raman and NMR spectroscopy as well as quantum chemical DFT calculations. X-ray diffraction studies of compound 2 revealed that the oxygen atom participates as donor and the antimony atom plays the role of acceptor, adopting a Ψ-distorted trigonal bi-pyramidal geometry, where the eight-membered central ring displays a boat–boat conformation. Furthermore, a series of DFT calculations was performed on compounds 1–3 as well as calculations on the non-synthesized heterotetracyclic systems [{S(C₆H₃S)₂O}SbF] (4a) and the cation [{S(C₆H₃S)₂O}Sb]⁺ (5a). The theoretic study at DFT level indicates as the electronegativity increases at exocyclic substituent along the set of compounds, the interaction is stronger. Moreover, the topological analysis of electronic density showed the existence of critical points along the O → Sb direction which prompted us to suggest the existence of a dative bond.     

Synthesis and biological activities of nitro-hydroxy-phenylquinolines; validation of antibiotics effect over DNA gyrase inhibition and antimicrobial activity

A family of 11 nitrophenol 2-nitro-5-(4-substituted phenylquinolin-2-yl)phenol derivatives (4, 4a-j) was effectively synthesized as antimicrobial medications. A mixture of the substituted 3-hydroxy-4-nitrobenzaldehyde substituted aromatic amine and substituted phenylacetylenes were used to synthesis the title compounds 4, 4a-j. Antimicrobialactivity potential of 4, 4a-j was evaluated against Streptococcus pyogenes (MTCC 442), Staphylococcus aureus (MTCC 96), Pseudomonas aeruginosa (MTCC 424), and Escherichia coli (MTCC 443). DNA gyrase inhibition studies carried out to understand the mechanism ofaction of the antimicrobial effect of target compounds. HRBC membrane stabilization (in vitro) property was also assessed as a representative human cellular cytotoxic effect of 4, 4a-j since HRBC alike lysosomal cells and the lysozyme activity leads to inflammation and its adverse effects in cellular systems. Results reveal that compounds 4c and 4h have remarkable antibacterial activity and screened for further preclinical studies.     

Voltammetric Simultaneous Determination of Cu2+, Cd2+ and Pb2+ in Full Aqueous Medium Using Organic Nanoparticles of Disulfide Based Receptor

Disulfide based receptor was prepared using single step condensation reaction and suspended into organic nanoparticles to extend its practical application in aqueous samples. The prepared nanoparticles were used for the simultaneous recognition of three different metallic species (Cu²⁺, Cd²⁺, and Pb²⁺) in aqueous media through voltammetric studies. These metals can be determined simultaneously and without interferences from any of the other potential interferent metal ions, as different signals are displayed in cyclic as well as differential pulse voltammograms, with a detection limit of 193.0 nM for Cu²⁺, 52.0 nM for Cd²⁺ and 32.0 nM for Pb²⁺. The study was extended to real sample analysis by preparing the artificial mixtures of said metal ions.     

Kinetics and mechanism for the oxidation of anilines by ClO2: a combined experimental and computational study

The oxidation of para‐substituted anilines (X–C₆H₄NH₂, X = –CH₃, –H, –Cl, –NO₂) with chlorine dioxide was studied as a means of eliminating these pollutants. The oxidation rate decreases from that for 4‐methylaniline to that for 4‐nitroanilinem in agreement with the Hammett plot; the oxidation kinetics is second order in aniline and first order in ClO₂, for which a possible mechanism is proposed. Liquid chromatography and gas chromatography mass spectrometry results show that benzoquinone is formed as the major intermediate in aniline/ClO₂ oxidation, and the reaction is pH‐dependent as the rate constant increases with increasing pH. To further support our proposed mechanism, Density Functional Theory (DFT) computations at both B3LYP/6‐311 + G(d,p) level with the polarizable continuum model with an integral equation formalism solvation model (i.e., with water) were carried out, showing that activation energy barriers predict the same reactivity trend as shown by the kinetics experiments. Copyright © 2014 John Wiley & Sons, Ltd.     

Nanohybrid Chemosensor for the Simultaneous Detection of Fluoride and Iodide in Aqueous System and Its Utility in Real Samples

A nanohybrid chemosensor for specific, selective and simultaneous recognition of iodide and fluoride was prepared through decoration of silver nanoparticles onto Schiff‐Base based organic nanoparticles. The developed chemosensor showed specific recognition ability for this analytes at low concentrations with detection limits at 690 nM for fluoride and 11 nM for iodide in two different regions of DPV profiles. Theoretical calculations based in Density Functional Theory were performed, which supports experimental results by demonstrating the binding selectivity of nanohybrids with I^? and F^?. The proposed sensor was also used for real sample analysis and results were verified using some standard literature method.