Halide-Doping Effect of Strontium Cobalt Oxide Electrocatalyst and the Induced Activity for Oxygen Evolution in an Alkaline Solution

Perovskites of strontium cobalt oxyhalides having the chemical formulae Sr2CoO4-xHx (H = F, Cl, and Br; x = 0 and 1) were prepared using a solid-phase synthesis approach and comparatively evaluated as electrocatalysts for oxygen evolution in an alkaline solution. The perovskite electrocatalyst crystal phase, surface morphology, and composition were examined by X-ray diffraction, a scanning electron microscope, and energy-dispersive X-ray (EDX) mapping. The electrochemical investigations of the oxyhalides catalysts showed that the doping of F, Cl, or Br into the Sr2CoO4 parent oxide enhances the electrocatalytic activity for the oxygen evolution reaction (OER) with the onset potential as well as the potential required to achieve a current density of 10 mA/cm2 shifting to lower potential values in the order of Sr2CoO4 (1.64, 1.73) > Sr2CoO3Br (1.61, 1.65) > Sr2CoO3Cl (1.53, 1.60) > Sr2CoO3F (1.50, 1.56) V vs. HRE which indicates that Sr2CoO3F is the most active electrode among the studied catalysts under static and steady-state conditions. Moreover, Sr2CoO3F demonstrates long-term stability and remarkably less charge transfer resistance (Rct = 36.8 ohm) than the other oxyhalide counterparts during the OER. The doping of the perovskites with halide ions particularly the fluoride-ion enhances the surface oxygen vacancy density due to electron withdrawal away from the Co-atom which improves the ionic and electronic conductivity as well as the electrochemical activity of the oxygen evolution in alkaline solution.

Antimicrobial Activity of Benzimidazoles Derivatives

The anti-microbial action of benzimidazole of ampicillin, was examined in Vitro beneath a specific conditions, utilizing the disc diffusion method, against different gram-positive and gram-negative pathogenic microorganisms such as Bacillus cereus, Staphylococcus aureus Pseudomonas aeruginosa and Escherichia Coli. An arrangement of these compounds were arranged and have appeared to hinder phthogenic development, the range of the zone of restraint. The zone of Obstacles of compounds founds from 7 mm2 to 46 mm2 Among the synthesized compounds in common. 6-Methoxy-N-phenyl- 1H-benzo [d]imidazol-2-amine(1c, zone of inhibition 9 mm2 at 40 µg/ml against Escherichia coli ) and 6-Chloro-N-phenyl-1H-benzo [d]imidazol-2-amine (1d, zone of inhibition 18 mm2 at 40 µg/ml against Bacillus cereus) have appeared great movement. While 1j, zone of inhibition 20 mm2 at 40 µg/ml), and (1i, zone of inhibition 20 mm2 at 40 µg/ml) were found to be displayed directly to great action against Bacillus cereus and Escherichia coli. 1p did not appear any movement against Staphylococcus aureus .1e did not appear any movement against Escherichia Coli and Staphylococcus aureus.The results have shown clearly that the contribution of el ectron -donation and electron- withdrawal to the aromatic ring i ncreases antibacterial activity. Target benzimidazolessamples sho wed antibacterial & reference antibiotic ampicillin in vitro.

Corrosion Inhibition Efficiency Of Nicotine Based On Quantum Chemical Study

The effect of substituents, electron donor groups (NH2, OH, CH2OH and CH3) and electron withdrawal groups (NO2, COOH, and Cl), to the efficiency of corrosion inhibition of nicotine has been studied using theoretical studies. The effect of substituents toward the efficiency of corrosion inhibition of nicotine based on quantum parameters (EHOMO, ELUMO, Egap, I, χ, dan ΔN). The efficiency of corrosion inhibition based on quantum parameters is NH2 > OH > CH2OH > CH3 > BN > Cl > COOH > NO2. The addition of electron donor group NH2 has the highest inhibitory efficiency of 99.79 %. In contrast, the presence of electron withdrawal group NO2 has the opposite effect.

Self-assembly of metal/semiconductor heterostructures via ligand engineering: unravelling the synergistic dual roles of metal nanocrystals toward plasmonic photoredox catalysis

A cooperative synergy arising from the SPR and electron-withdrawal effects of gold nanocrystals was simultaneously and unambiguously unraveled for plasmonic photoredox catalysis.

Efficient Microwave-Assisted Solvent-Free Synthesis and Molecular Docking Studies of 2-pyridone derivatives as Anticancer Agents and Evaluation of Cytotoxic Effects

Introduction: A green protocol will be used to synthesize a novel series of 3-cyano-5- arylazo-pyridones (9a-c) and (10d-i). Methodology: Structures of the new products will be confirmed on the basis of spectroscopic data (FT-IR, 1D, NMR) as well as alternative synthetic routes, anticancer cell-line will be investigated and also molecular docking studies will be applied. Results: The activity against different cancer cell-line will be studied. Compounds with electron withdrawal group showed the highest activities.

A photoelectrochemical sensor through quenching of photoinduced electrons based on a G-quadruplex/hemin complex

A novel label-free photoelectrochemical sensor was fabricated for the detection of K+ based on the electron withdrawal effect of hemin. The decreasing photocurrent from photoinduced electron transfer by a G-quadruplex/hemin complex was utilized.

An efficient regioselective bromination protocol of activated coumarins using 2,4,4,6-tetrabromo-2,5-cyclohexadienone

2,4,4,6-Tetrabromo-2,5-cyclohexadienone mediated bromination of a wide assortment of activated coumarins in acetonitrile has been accomplished with high regioselectivity and good to excellent yields. The selectivity and efficiency of bromination were found to be markedly dependent on electronic factors, particularly degree of electron withdrawal from electron-releasing 7-oxygenated substituents to the C-3 position of the α-pyrone moiety by vinylogous resonance and the presence of nucleophilic additives such as water and tetra-n-butylammonium bromide in the reaction medium. The sole by-product of the reaction was converted back to the reagent by oxidation with KBr−KBrO3, which was recycled three times without significant loss of efficiency.

DENSITY FUNCTIONAL STUDY ON THE EFFECT OF ELECTRON WITHDRAWING SUBSTITUENT ON THE STABILITY OF RNHBH2

We investigated the stability of aminoborane with electron withdrawing groups such as – CF 3 and – CN using density functional theory calculations. For the electron withdrawing groups of – CF 3 and – CN , we observed similar tendency of B – N bond strength: electron withdrawal from the N atom reduces the strength of B – N bonds. And we find that the electron density localized on B and N is also reduced through the charge analysis. These electron withdrawing substituents make cyclic dimers and trimers stabilized less than electron donating ones.