In this paper a new schiff base ligand and its complex containing Mn(Ⅱ) were synthesized by the condensating 5-chloro salicylaldehyde with suphourea.Its composition and structure have been characterized by the elemen...In this paper a new schiff base ligand and its complex containing Mn(Ⅱ) were synthesized by the condensating 5-chloro salicylaldehyde with suphourea.Its composition and structure have been characterized by the elemental analysis and several spectra.The free radical inhibition rate to O - 2 have also been tested.展开更多
Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods, such as cyclic voltammetry, chronopotentiometry, AC impedance, linear sweep voltammetry. Apparent activation ...Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods, such as cyclic voltammetry, chronopotentiometry, AC impedance, linear sweep voltammetry. Apparent activation energy of anodic process of gold electrode dissolving in alkaline thiourea solution is 14.91 kJ/moh Rate determining step is the process of gold thiourea complex diffusing away from electrode surface to solution. The results of AC impedance and chronopotentiometry indicate that thiourea adsorbs on gold electrode surface before dissolving in solution. There does not exist proceeding chemical reactions. Formamidine disulfide, the decomposed product of thiourea, does not participate the process of gold dissolution and thiourea complex. Species with electro-activity produced in the process of electrode reaction adsorbs on the electrode surface. In alkaline thiourea solution, gold dissolving mechanism undergoes the following courses： adsorption of thiourea on electrode surface; charge transfer from gold atom to thiourea molecule; Au[SC（NH2）2]ads^＋ receiving a thiourea molecule and forming stable Au[SC（NH2）2]2^＋; and then Au[SC（NH2）2]2^＋ diffusing away from the electrode surface to solution, the last step is the rate-determining one.展开更多
Kinetic parameters of the electrode reactions were measured by investigating steady-state current-potential behaviors. The results show that the apparent transfer coefficient of anodic process is 0.0582, diffusion coe...Kinetic parameters of the electrode reactions were measured by investigating steady-state current-potential behaviors. The results show that the apparent transfer coefficient of anodic process is 0.0582, diffusion coefficient of thiourea gold complex is 6.04×10~ -6 cm^2/s,anodic reaction order of thiourea is 2.0183, and anodic reaction order of OH^- is 0.0166. The theoretical kinetics equation of gold dissolving in alkaline thiourea solution is deduced, which indicates that anodic reaction order of thiourea is 2, and anodic reaction order of OH^- is 0. The theoretical values of the kinetic parameters are consistent with experimental values very well. The correctness of the mechanism is further demonstrated using apparent transfer coefficient according to the electrochemical dynamic equation of multi-electron reaction.展开更多
文摘In this paper a new schiff base ligand and its complex containing Mn(Ⅱ) were synthesized by the condensating 5-chloro salicylaldehyde with suphourea.Its composition and structure have been characterized by the elemental analysis and several spectra.The free radical inhibition rate to O - 2 have also been tested.
基金Project(50004009) supported by the National Natural Science Foundation of China
文摘Reaction mechanism of gold dissolving in alkaline thiourea solution was studied by electrochemical methods, such as cyclic voltammetry, chronopotentiometry, AC impedance, linear sweep voltammetry. Apparent activation energy of anodic process of gold electrode dissolving in alkaline thiourea solution is 14.91 kJ/moh Rate determining step is the process of gold thiourea complex diffusing away from electrode surface to solution. The results of AC impedance and chronopotentiometry indicate that thiourea adsorbs on gold electrode surface before dissolving in solution. There does not exist proceeding chemical reactions. Formamidine disulfide, the decomposed product of thiourea, does not participate the process of gold dissolution and thiourea complex. Species with electro-activity produced in the process of electrode reaction adsorbs on the electrode surface. In alkaline thiourea solution, gold dissolving mechanism undergoes the following courses： adsorption of thiourea on electrode surface; charge transfer from gold atom to thiourea molecule; Au[SC（NH2）2]ads^＋ receiving a thiourea molecule and forming stable Au[SC（NH2）2]2^＋; and then Au[SC（NH2）2]2^＋ diffusing away from the electrode surface to solution, the last step is the rate-determining one.
基金Project(50004009) supported by the National Natural Science Foundation of China
文摘Kinetic parameters of the electrode reactions were measured by investigating steady-state current-potential behaviors. The results show that the apparent transfer coefficient of anodic process is 0.0582, diffusion coefficient of thiourea gold complex is 6.04×10~ -6 cm^2/s,anodic reaction order of thiourea is 2.0183, and anodic reaction order of OH^- is 0.0166. The theoretical kinetics equation of gold dissolving in alkaline thiourea solution is deduced, which indicates that anodic reaction order of thiourea is 2, and anodic reaction order of OH^- is 0. The theoretical values of the kinetic parameters are consistent with experimental values very well. The correctness of the mechanism is further demonstrated using apparent transfer coefficient according to the electrochemical dynamic equation of multi-electron reaction.
