Effect of Concentration of TiO Nanoparticles on Thiadiazole Derivative and Their Molecular Docking Study.

In the present work, we report the synthesis of TiO nanoparticles by hydrothermal method using titanium isopropoxide. The synthesized TiO nanoparticles were investigated by Powder X-ray diffraction, FE-SEM with EDX, Photoluminescence, UV-Visible absorption and Fluorescence emission spectroscopy. Fluorescence intensity and absorption values of 4-[5-(2,5-Dimethyl-pyrrol-1-yl)-[1,3,4]thiadiazol-2-ylsulfanylmethyl]-6-methoxy-chromen-2-one (DTYMC) molecule decreases with adding the concentration of TiO nanoparticles.

Optimization of anti-corrosion performance of novel magnetic polyaniline-Chitosan nanocomposite decorated with silver nanoparticles on Al in simulated acidizing environment using RSM.

The suitability of newly synthesized magnetic polyaniline-Chitosan nanocomposite decorated with silver nanoparticles (Ag@PANI-CS-FeO) as a robust corrosion inhibitor for Aluminum (Al) in a 5 M HCl environment has been investigated via Weight Loss (WL), Alternating Current (AC)-Impedance Spectroscopy (IS), Potentiontiodynamic polarization (Tafel plots), and Scanning Electron Microscopy (SEM) techniques. The protection efficiency (PE) was mathematically modeled using the Response Surface Methodology (RSM) to fit an empirical relation in terms of temperature, nanocomposite concentration, and time using the face-centered central composite design. The model was accurate with a coefficient of determination (R = 99.

Computational and spectroscopic studies of biologically active coumarin-based fluorophores.

We used density functional theory (DFT) calculations to examine the various molecular properties of two coumarin derivatives, namely 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-7-methyl-chromen-2-one and 4-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-7-methoxy-chromen-2-one at different levels of theory and basis sets. The calculated highest occupied molecular orbital and lowest unoccupied molecular orbital energies revealed that the investigated molecules were chemically active with a tendency for molecular interactions. The theoretical vibrational frequencies of these molecules were found to be consistent with the experimentally obtained frequencies.

Study of Photophysical Properties on Newly Synthesized Coumarin Derivatives.

Herein, we have studied the photophysical properties for three newly synthesized coumarin derivatives; 4-((2,6-dibromo-4-methylphenoxy)methyl)-2H-benzo[h]chromen-2-one (DMB), 4-((3,4-dihydro-6,7-dimethoxyisoquinolin-1-yl)methyl)-6-methyl-2H-chromen-2-one (DIM) and 4-((p-tolyloxy)methyl)-6-methoxy-2H-chromen-2-one (TMC). The absorption and emission spectra for above said molecules were recorded in different solvents at room temperature in order to calculate their ground and excited state dipole moments. The ground (μ ) and excited state dipole (μ ) moments of these coumarin derivatives were calculated using Lippert's, Bakshiev's and Kawski-Chamma-Viallet's equations by the solvatochromic shift method, which involves a variation of Stokes shift with the solvent dielectric constant and refractive index.

Photophysical Properties of a Novel and Biologically Active 3(2H)-Pyridazinone Derivative Using Solvatochromic Approach.

Herein, we report photophysical properties of a novel and biologically active 3(2H)-pyridazinone derivative 5-(4-chloro-2-hydoxy-phenyl)-2-phenyl-2H-pyridazin-3-one [CHP] molecule using solvatochromic approaches. Absorption and fluorescence spectra of CHP molecule have been measured at room temperature in various solvents of different polarities. From this, it is observed that the positions, intensities and shapes of the absorption and emission bands are usually modified.

Analysis of Fluorescence Quenching for Newly Synthesized Biologically Active 3(2H)-pyridazinone Derivative by Aniline.

Herein, we have studied the analysis of fluorescence quenching for newly synthesized biologically active 3(2H)-pyridazinone derivative 5-(5-bromo-2-hydroxy-phenyl)-2-phenyl-2H-pyridazin-3-one [BHP] by various concentrations of aniline using UV-Visible spectroscopy, fluorescence spectroscopy and time-correlated single photon counting technique in five different solvents namely, methanol, ethanol, propan-2-ol, dimethylsulfoxide and ethyl acetate at room temperature. The fluorescence intensity of BHP molecule decrease with increasing in the aniline concentration and it is studied using the Stern-Volmer relation. The obtained Stern-Volmer plots were found to be linear in all the five solvents.

Effect of TiO nanoparticles on some photophysical characteristics of ketocyanine dyes.

The effect of titanium dioxide (TiO ) nanoparticles (NPs) on photophysical characteristics of 2,5-di[(E)-1-(4-dimethylaminophenyl) methylidine]-1-cyclopentanone (2,5-DMAPMC) and 2,5-di[(E)-1-(4-diethylaminophenyl)methylidine]-1-cyclopentanone (2,5-DEAPMC) ketocyanine dyes has been studied using absorption, steady-state and time-resolved fluorescence spectroscopy. The magnitudes of association constants determined based on modified absorption spectrum of dyes due to the presence of TiO NPs indicate the interaction of TiO NPs with dye molecules. The quenching of fluorescence intensity of dyes by TiO NPs is observed and it follows linear Stern-Volmer (S-V) equation.

Solvent Effects on the Electronic Absorption and Fluorescence Spectra of HNP: Estimation of Ground and Excited State Dipole Moments.

We report the effect of solvents on absorption and fluorescence spectra of biologically active 3(2H)-pyridazinone namely 5-(2-hydroxy-naphthalen-1-yl)-2-phenyl-2H-pyridazin-3-one (HNP) in different solvents at room temperature. The ground and the excited state dipole moments of HNP molecule was estimated from Lippert's, Bakshiev's and Kawski-Chamma-Viallet's equations using the solvatochromic shift method. The ground state dipole moment (μ g ) was also estimated by Guggenheim and Higasi method using the dielectric constant and refractive index of solute at different concentrations, the μ g value obtained from these two methods are comparable to the μ g value obtained by the solvatochromic shift method.

Investigation of role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4PTMBC and 1IPMBC.

The role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4-p-tolyloxymethyl-benzo[h]coumarin (4PTMBC) and 1-(4-iodophenoxymethyl)-benzo[f]coumarin (1IPMBC) has been investigated using absorption and fluorescence spectroscopy. Silver nanoparticles are synthesized by chemical reduction method and the estimated size by Mie theory is 12 nm. The absorption spectral changes of dyes in the presence of silver nanoparticles suggest their possible interaction with silver nanoparticles.

Photophysical characteristics of biologically active 4-aryloxymethyl coumarins 4PTMBC and 1IPMBC.

The absorption and fluorescence characteristics of biologically active coumarin derivatives 4-p-tolyloxymethyl-benzo[h]coumarin (4PTMBC) and 1-(4-iodo phenoxymethyl)-benzo[f]coumarin (1IPMBC) are studied at room temperature in a series of organic solvents and 1,4-dioxane - acetonitrile solvent mixture. The effect of pure solvents on the spectral properties are analyzed using Lippert-Mataga polarity function, Reichardt's microscopic solvent polarity parameter, Kamlet's and Catalan's multiple linear regression approaches. Both general solute - solvent interactions and hydrogen bonding interactions are operative in these systems.