Mechanism of Homogeneous Reduction of CO2by Pyridine: Proton Relay in Aqueous Solvent and Aromatic Stabilization

2012 ◽  
Vol 135 (1) ◽  
pp. 142-154 ◽  
Author(s):  
Chern-Hooi Lim ◽  
Aaron M. Holder ◽  
Charles B. Musgrave
Keyword(s):  
Proton Relay ◽  
Aqueous Solvent ◽  
Homogeneous Reduction ◽  
Aromatic Stabilization

Quantitative Structure-activity Relationship Analysis for Predicting Lipophilicity of Aniline Derivatives (Including some Pharmaceutical Compounds)

2019 ◽  
Vol 22 (5) ◽  
pp. 333-345
Author(s):  
Morteza Rezaei ◽  
Esmat Mohammadinasab ◽  
Tahere Momeni Esfahani
Keyword(s):  
Density Functional ◽  
Pharmaceutical Compounds ◽  
Partial Least Square ◽  
Least Square ◽  
Basis Set ◽  
Van Der Waals Volume ◽  
Relationship Analysis ◽  
Aniline Derivatives ◽  
Aqueous Solvent ◽  
Qsar Models

Background: In this study, we used a hierarchical approach to develop quantitative structureactivity relationship (QSAR) models for modeling lipophilicity of a set of 81 aniline derivatives containing some pharmaceutical compounds. Objective: The multiple linear regression (MLR), principal component regression (PCR) and partial least square regression (PLSR) methods were utilized to construct QSAR models. Materials & Methods: Quantum mechanical calculations at the density functional theory level and 6- 311++G** basis set were carried out to obtain the optimized geometry and then, the comprehensive set of molecular descriptors was computed by using the Dragon software. Genetic algorithm (GA) was applied to select suitable descriptors which have the most correlation with lipophilicity of the studied compounds. Results: It was identified that such descriptors as Barysz matrix (SEigZ), hydrophilicity factor (Hy), Moriguchi octanol-water partition coefficient (MLOGP), electrophilicity (ω/eV) van der Waals volume (vWV) and lethal concentration (LC50/molkg-1) are the best descriptors for QSAR modeling. The high correlation coefficients and the low prediction errors for MLR, PCR and PLSR methods confirmed good predictability of the three models. Conclusion: In present study, the high correlation between experimental and predicted logP values of aniline derivatives indicated the validation and the good quality of the resulting three regression methods, but MLR regression procedure was a little better than the PCR and PLSR methods. It was concluded that the studied aniline derivatives are not hydrophilic compounds and this means these compounds hardly dissolve in water or an aqueous solvent.

Study of Photocatalytic Dergradation, Kinetics and Microbial Activities of Copper (ii) Soya Urea Complex in Non Aqueous Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Staphylococcus Aureus ◽  
Photocatalytic Degradation ◽  
Degradation Kinetics ◽  
Waste Water Treatment ◽  
Aqueous Media ◽  
Research Work ◽  
Solvent Polarity ◽  
Urea Complex ◽  
Pseudo First Order Reaction ◽  
Aqueous Solvent

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics and microbial activity of new surfactant Copper (II) soya urea complex(CSU). Background: Photocatalytic degradation has attracted the attention of scientific community throughout the world due to its multiple applications in environment, energy, waste water treatment, pollution control, green chemistry, etc. Copper (II) soya urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Present work deals with the study of photocatalytic degradation of Copper (II) soya urea complex by using ZnO as semiconductor. This study employs a semiconductor catalyst using non polar and non aqueous solvent in photocatalytic degradation. Reaction rate is chosen as the photocatalytic activity, which has been governed by several factors. Antibacterial activities of Copper (II) complex have also been studied against Staphylococcus aureus. Method: Optical density (O.D.) was measured after different time intervals spectrophotometrically to measure the degradation of complex. Mueller-Hinton agar medium was used for antimicrobial activity of synthesized compound at different concentrations by disk/ well diffusion susceptibility testing. Result: Plot of 2+log O.D. (absorbance) versus time was plotted and found linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics.The present study suggests that Copper (II) soya urea (CSU) complex shows antibacterial activity against Staphylococcus aureus at different concentrations. Conclusion: The results were used to determine the rate of photocatalytic degradation of CSU complex .It has been found that rate of degradation varies with different parameters like concentration of complex, amount of catalyst, light intensity, solvent polarity etc. CSU complex derived from soyabean oil has been shown an inhibitory effect on the growth of S. aureus which may causes skin disease.

A bio-inspired mononuclear manganese catalyst for high-rate electrochemical hydrogen production

2021 ◽  
Vol 50 (14) ◽  
pp. 4783-4788
Author(s):  
Jie Yang ◽  
Shuanglin He ◽  
Qianqian Wu ◽  
Ping Zhang ◽  
Lin Chen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Electrochemical Measurements ◽  
High Rate ◽  
Turnover Frequency ◽  
Molecular Catalyst ◽  
Proton Relay ◽  
Excellent Activity

A bio-inspired manganese molecular catalyst featuring an intramolecular aniline as a proton relay was synthesized and used for hydrogen production. Electrochemical measurements with this complex show excellent activity (turnover frequency over 104 s−1).

scholarly journals Cellulose Paper Modified by a Zinc Oxide Nanosheet Using a ZnCl2-Urea Eutectic Solvent for Novel Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1111
Author(s):  
Changmei Lin ◽  
Duo Chen ◽  
Zifeng Hua ◽  
Jun Wang ◽  
Shilin Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Cellulose Fibers ◽  
Human Motion ◽  
Triboelectric Nanogenerator ◽  
Crystalline Region ◽  
Ptfe Film ◽  
Cellulose Paper ◽  
Output Performance ◽  
Aqueous Solvent

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation.

scholarly journals Room Temperature Syntheses of ZnO and Their Structures

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 733
Author(s):  
Domenica Donia ◽  
Elvira Maria Bauer ◽  
Mauro Missori ◽  
Ludovica Roselli ◽  
Daniele Cecchetti ◽  
...  
Keyword(s):  
Room Temperature ◽  
Direct Synthesis ◽  
Threshold Value ◽  
Rietveld Analysis ◽  
Synthesis Temperature ◽  
Density Variation ◽  
Controlled Synthesis ◽  
Sem Images ◽  
Aqueous Solvent ◽  
Average Size

ZnO has many technological applications which largely depend on its properties, which can be tuned by controlled synthesis. Ideally, the most convenient ZnO synthesis is carried out at room temperature in an aqueous solvent. However, the correct temperature values are often loosely defined. In the current paper, we performed the synthesis of ZnO in an aqueous solvent by varying the reaction and drying temperatures by 10 °C steps, and we monitored the synthesis products primarily by XRD). We found out that a simple direct synthesis of ZnO, without additional surfactant, pumping, or freezing, required both a reaction (TP) and a drying (TD) temperature of 40 °C. Higher temperatures also afforded ZnO, but lowering any of the TP or TD below the threshold value resulted either in the achievement of Zn(OH)2 or a mixture of Zn(OH)2/ZnO. A more detailed Rietveld analysis of the ZnO samples revealed a density variation of about 4% (5.44 to 5.68 gcm−3) with the synthesis temperature, and an increase of the nanoparticles’ average size, which was also verified by SEM images. The average size of the ZnO synthesized at TP = TD = 40 °C was 42 nm, as estimated by XRD, and 53 ± 10 nm, as estimated by SEM. For higher synthesis temperatures, they vary between 76 nm and 71 nm (XRD estimate) or 65 ± 12 nm and 69 ± 11 nm (SEM estimate) for TP =50 °C, TD = 40 °C, or TP = TD = 60 °C, respectively. At TP = TD = 30 °C, micrometric structures aggregated in foils are obtained, which segregate nanoparticles of ZnO if TD is raised to 40 °C. The optical properties of ZnO obtained by UV-Vis reflectance spectroscopy indicate a red shift of the band gap by ~0.1 eV.

EFFECTS OF COMPLEXING ON THE HOMOGENEOUS REDUCTION OF MERCURIC SALTS IN AQUEOUS SOLUTION BY MOLECULAR HYDROGEN

1956 ◽  
Vol 34 (10) ◽  
pp. 1372-1381 ◽  
Author(s):  
G. J. Korinek ◽  
J. Halpern
Keyword(s):  
Aqueous Solution ◽  
Molecular Hydrogen ◽  
Hydrogen Molecule ◽  
Bimolecular Reaction ◽  
Mercury Atom ◽  
Complexing Agents ◽  
Mercuric Ion ◽  
Rate Determining Step ◽  
Homogeneous Reduction

The effects of various complexing agents on the homogeneous reduction of mercuric salts by molecular hydrogen in aqueous solution were determined. In all cases the kinetics suggest that the rate-determining step is a bimolecular reaction between a mercuric ion or complex and a hydrogen molecule, probably leading to the formation of an intermediate mercury atom. The reactivity of various mercuric complexes was found to decrease in the following order: HgSO4 > Hg++ > HgAc2, HgPr2 > HgCl2 > HgBr2 > Hg(EDA)2++. Addition of anions such as OH−, CO3=, Ac−, Pr−, and Cl−, in excess of the amounts required to form stable mercuric complexes, was found to increase the rate. An interpretation of these effects is given.

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