An Insight into Photophysical Investigation of (E)-2-Fluoro-N'-(1-(4-Nitrophenyl)Ethylidene)Benzohydrazide through Solvatochromism Approaches and Computational Studies.

A fluoro-based Schiff base (E)-2-fluoro-N'-(1-(4-nitrophenyl)ethylidene)benzohydrazide (FNEB) has been synthesized from condensation of 2-fluorobenzohydrazide and 4'-nitroacetophenone catalyzed by glacial acetic acid with ethanol as the solvent. The dipole moment of FNEB in both the electronic states were found using different solvatochromic approaches such as Lippert-Mataga, Bakhshiev, Kawski-Chamma-Viallet, Reichardt and Bilot-Kawski. The experimental ground state dipole moment of FNEB was calculated using Guggenheim-Debye method and theoretical ground state dipole moment using Bilot-Kawski solvatochromic approach. The solvatochromic behavior of the Schiff base in different solvents was studied using absorption and emission spectra. Catalan and Kamlet-Abboud-Taft parameters were used from the multiple linear regression (MLR) analysis in order to study the solute-solvent interaction. The dipole moments were also calculated using Time Dependent-Density Functional Theory (TD-DFT). The chemical stability of FNEB was determined using computational and Cyclic Voltammetry by the use of obtained energy gap between the frontier orbitals. Using the frontier orbitals energy gap, global reactivity parameters were computed. Further, Light Harvesting efficiency was determined to comprehend the photovoltaic property of the Schiff base.

Study on Photophysical Properties of N-Arylphthalamic Acid Derivative Containing 1, 2, 4-Triazole Scaffold.

A novel N-arylphthalamic acid derivative, 2-({4-[(1H-1,2,4-triazol-1-yl)methyl]phenyl}carbamoyl)benzoic acid (TMPCB) was synthesized and their absorption and emission spectra were recorded in fifteen different solvents of varying polarities at room temperature. Ground state dipole moment of the derivative was calculated experimentally by Guggenheim method and solvatochromic approach proposed by Bilot-Kawski. The singlet excited state dipole moment of TMPCB were calculated experimentally based on different approaches of solvent polarity function proposed by Lippert-Mataga, Bakhshiev, Kawskii-Chamma-Viallet, Reichardt and Bilot-Kawski. Singlet excited state dipole moment was greater than ground state dipole moment in all the approaches which could be attributed to considerable π- electron density redistribution. Multiple Linear Regression (MLR) analysis based on Kamlet-Abboud-Taft and Catalan parameters were also studied to correlate solvatochromism and influence of solvents with absorbance and emission spectra. Ground and singlet excited state optimizations of the molecule were also performed using Gaussian 09 W software. HOMO-LUMO energies of the phthalamic acid derivative have been obtained using TD-DFT/PCM (B3LYP/6-31G (d, p)) computations and experimentally by using cyclic voltammetry. Mulliken charges and molecular electrostatic potential plot have also been generated from DFT calculations to identify nucleophilic and electrophilic sites of TMPCB.

Electrochemical sensing of vitamin B12 deficiency marker methylmalonic acid using PdAu-PPy tailored carbon fiber paper electrode.

Vitamin B12 is very important for human metabolism and its deficiency can cause anemia and the production of large red blood cells. An increased concentration of methylmalonic acid (MMA) is detected much before the transformation of blood cells, which thereby is an early indicator for mild or serious Vitamin B12 deficiency. A simple electrochemical sensor based on Palladium-Gold (PdAu) was developed by electrodeposition of PdAu nanoparticles on Polypyrrole (PPy) modified carbon fiber paper (CFP) electrode. The modified electrodes were characterized by High resolution transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electroanalytical techniques. Differential Pulse Voltammetric (DPV) studies have established that under optimum conditions, the developed sensor exhibits a broad linear dynamic range (4.01 pM - 52.5 nM) with a very low detection limit (1.32 pM). The proposed method was effectively applied in the non-enzymatic determination of MMA at an ultralow level in human blood serum and urine samples. The method displayed high selectivity toward MMA in the presence of other interfering substances.

Electrocatalytic oxidation of morin on electrodeposited Ir-PEDOT nanograins.

Nanoclusters of Ir were electrochemically deposited on carbon fiber paper (CFP) substrate modified with poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer between the potential range 0.0 V and 0.6 V at 0.05 V/s scan rate. The electrocatalytic activity of Ir-PEDOT/CFP electrode towards oxidation of morin, a flavonoid was significantly greater than that of PEDOT/CFP and bare CFP electrodes. Factors affecting the anodic peak of morin namely, effect of pH, scan rate and number of cycles were optimized. The electrochemical route involved adsorption controlled and irreversible processes. Under optimal conditions, the linear dynamic range for the determination of morin was found to be 0.12 nM-2.80 nM. The significantly low detection limit (42.18 pM) demonstrates the ultrasensitivity of the proposed method. The reliability of the method was evaluated for the quantification of morin present in mulberry leaves, guava leaves and grape wine.