The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, ...The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol;and the reaction heat being 10.06 kJ·mol;. The dominant product predicted theoretically is in agreement with the experiment results.展开更多
The practical use of non-conducting poly(o-aminophenol) (POAP) films in the field of the bioelectrochemistry is discussed in this paper. Particular emphasis is given to the effects of applied potential, solution pH an...The practical use of non-conducting poly(o-aminophenol) (POAP) films in the field of the bioelectrochemistry is discussed in this paper. Particular emphasis is given to the effects of applied potential, solution pH and interferents on the response current of biosensors based on POAP.展开更多
Extraction of o-aminophenol (OAP) using trialkylphosphine oxide (TRPO) was studied with different diluents. The neutral OAP was extracted using TRPO under an equilibrium pH in the range of 6—7.5, and a maximum distri...Extraction of o-aminophenol (OAP) using trialkylphosphine oxide (TRPO) was studied with different diluents. The neutral OAP was extracted using TRPO under an equilibrium pH in the range of 6—7.5, and a maximum distribution coefficient occurred. It was confirmed that the pH value and the TRPO concentration are the key factors that affect dis-tribution coefficient. Nonpolar diluents could provide better extraction distribution coefficient for the extraction of OAP and the order is: kerosene >n-octanol >chloroform.展开更多
The Ni 2+/poly（o-aminophenol）electropolymerization was carried out by a continuous cyclic voltammetric scanning at a carbon paste electrode in a mixture of 0.02 mol/L o-aminophenol,0.3 mol/L NiSO 4 and 0.6 mol/L HCl...The Ni 2+/poly（o-aminophenol）electropolymerization was carried out by a continuous cyclic voltammetric scanning at a carbon paste electrode in a mixture of 0.02 mol/L o-aminophenol,0.3 mol/L NiSO 4 and 0.6 mol/L HClO 4.dsDNA was linked to the conducting polymer via three-dimensional structure of polymer film and electrostatic attraction between the negatively charged phosphate backbone of DNA and Ni 2+ ion.The results were testified by the electrochemical methods by using Co（phen）2+3 as an electrochemical indicator.The currents of redox peaks of Co（phen）2+3 increased after immobilizing dsDNA.The conditions for the preparation of Ni 2+/P-OAP/CPE and DNA immobilization were optimized.The voltammetric behavior of dopamine was investigated at the modified electrode.It was found that the modified electrode exhibited a highly electrocatalytic activity toward dopamine oxidation.Differential pulse voltammetry was used for determination of dopamine in pH 5.1 phosphate buffer solution.A linear response of the peak current versus the concentration was found in the range from 5.0×10-6 to 2.0×10-4mol/L with 1.0×10-2 mol/L AA（ascorbic acid）coexisting.The presence of a high concentration of AA did not interfere with the determination.The proposed method exhibits a good recovery and reproducibility.展开更多
基金Supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1601215)the Ministry of Education "Chunhui Plan"(Z2016177)
文摘The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol;and the reaction heat being 10.06 kJ·mol;. The dominant product predicted theoretically is in agreement with the experiment results.
文摘The practical use of non-conducting poly(o-aminophenol) (POAP) films in the field of the bioelectrochemistry is discussed in this paper. Particular emphasis is given to the effects of applied potential, solution pH and interferents on the response current of biosensors based on POAP.
基金Supported by the Educational Department of Henan Province (No.2004530001).
文摘Extraction of o-aminophenol (OAP) using trialkylphosphine oxide (TRPO) was studied with different diluents. The neutral OAP was extracted using TRPO under an equilibrium pH in the range of 6—7.5, and a maximum distribution coefficient occurred. It was confirmed that the pH value and the TRPO concentration are the key factors that affect dis-tribution coefficient. Nonpolar diluents could provide better extraction distribution coefficient for the extraction of OAP and the order is: kerosene >n-octanol >chloroform.
文摘The Ni 2+/poly（o-aminophenol）electropolymerization was carried out by a continuous cyclic voltammetric scanning at a carbon paste electrode in a mixture of 0.02 mol/L o-aminophenol,0.3 mol/L NiSO 4 and 0.6 mol/L HClO 4.dsDNA was linked to the conducting polymer via three-dimensional structure of polymer film and electrostatic attraction between the negatively charged phosphate backbone of DNA and Ni 2+ ion.The results were testified by the electrochemical methods by using Co（phen）2+3 as an electrochemical indicator.The currents of redox peaks of Co（phen）2+3 increased after immobilizing dsDNA.The conditions for the preparation of Ni 2+/P-OAP/CPE and DNA immobilization were optimized.The voltammetric behavior of dopamine was investigated at the modified electrode.It was found that the modified electrode exhibited a highly electrocatalytic activity toward dopamine oxidation.Differential pulse voltammetry was used for determination of dopamine in pH 5.1 phosphate buffer solution.A linear response of the peak current versus the concentration was found in the range from 5.0×10-6 to 2.0×10-4mol/L with 1.0×10-2 mol/L AA（ascorbic acid）coexisting.The presence of a high concentration of AA did not interfere with the determination.The proposed method exhibits a good recovery and reproducibility.
