نتایج جستجو برای: anions

تعداد نتایج: 29584  

2006
SUNG-WOO PARK SUK IM SUNGYUL LEE C. DESFRANÇOIS

Calculations are presented for the glycine–(H2O)3 cluster anion, with glycine in canonical or zwitterionic form. The zwitterionic anions are predicted to be considerably lower in energy than the canonical anions, and the latter forms are found to be prone to isomerization to the zwitterionic anions. Therefore, we predict that the zwitterionic anions would be observed predominantly in the gas ph...

Journal: :The Journal of organic chemistry 2010
Michael H Abraham William E Acree

Partition coefficients from water to organic solvents for phenoxide anions have been obtained using a method based on the variation of pK(a) of phenols with solvent. From these partition coefficients, the Abraham descriptors for phenoxide anions, on the same scale as descriptors for neutral molecules, have been obtained. Equations have been constructed for the prediction of descriptors, and val...

The influence of benzoate anions on the corrosion inhibition effect of benzotriazole (BTA) for mild steel in sulfuric acid has been investigated. The investigation was carried out by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The addition of benzoate ions greatly enhances the inhibition efficiency of BTA in a synergistic manner. This effect has bee...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2011
Toyohide Takeuchi Lee Wah Lim

Inorganic anions were separated on a reversed-phase stationary phase dynamically modified with crown ether as a selector in capillary ion chromatography. The eluent contained crown ether, acetonitrile and a salt. Free and cation-trapped crown ether molecules in the eluent were adsorbed on a hydrophobic stationary phase such as triacontyl-functionalized silica (C30). The eluent cations trappe...

Density functional theory dispersion corrected (DFT-D3)calculations and molecular dynamic (MD) simulation were applied to investigate the sensing ability of four types of receptors (RCs) composed of the ortho-phenylenediamine based bis-ureas for selective complexation with the anions such as Cl–, Br–, OAC–, PhCO2–, H2PO4– and HSO4– in the gas phase and DMSO. On the basis of the data obtained fr...

2015
Eric T. Kool

Many existing irrigation, industrial and chemical storage sites are currently introducing hazardous anions into groundwater, making the monitoring of such sites a high priority. Detecting and quantifying anions in water samples typically requires complex instrumentation, adding cost and delaying analysis. Here we address these challenges by development of an optical molecular method to detect a...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2012
Lee Wah Lim Li Rong Toyohide Takeuchi

The present article reviews the use of polyethylene glycol (PEG) or polyoxyethylene (POE) as the stationary phase for the separation of inorganic anions in ion chromatography and discusses about the retention mechanisms involved in the separation of anions on the novel stationary phases. PEG permanently coated on a hydrophobic stationary phase retained anions in the partition mode and allowed ...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2014
hossein faghihian marzieh rasekh

unmodified zeolites show little affinity for anions due to the fact that their surfaces are negatively charged. however modification of zeolites with amines turns their negative surface charge to positive and creating higher adsorption capacity for anions. in this study, polyaniline-clinoptilolite composite was prepared by polymerization of anilinium on the surface of zeolite. the composite was...

Journal: :Journal of the Japan Society of Colour Material 2007

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