Effect of copper(II) ions on kinetics of ascorbic acid oxidation by methylene blue
Tóm tắt
A kinetic scheme is proposed for the reduction of methylene blue by ascorbic acid in the presence of copper(II) ions. The introduction of copper(II) ions increases the reaction rate, owing to the increased concentration of ascorbic acid radicals in the solution. It is shown that the inhibition of the reaction that is observed with low concentrations of copper(II) is a result of redox reactions proceeding in the system, involving oxygen dissolved in the water.
Tài liệu tham khảo
K. B. Yatsimirskii, L. N. Zakrevskaya, P. E. Strizhak, and E. V. Rybak-Akimova, Chem. Phys. Lett., 186, No. I, 15–18 (1991).
P. E. Strizhak, Teor. Éksp. Khim., 29, No. 5, 424–429 (1993).
K. M. M. Taqui and A. E. Martell, J. Am. Chem. Soc., 89, No. 16, 4174–4185 (1967).
J. Zu and R. B. Jordan, Inorg. Chem., 29, No. 16, 2933–2936 (1990).
Y. Luo, M. Orban, K. Kustin, and I. R. Epstein, J. Am. Chem. Soc., 111, No. 3, 4541–4548 (1989).
A. Ya. Sychev, Redox Catalysis by Metal Complexes [in Russian], Shtiintsa, Kishinev (1976).
Y.-X Zhang and R. J. Field, J. Phys. Chem., 95, No. 2, 723–727 (1991).
B. G. Cox, J. Wojciech, and P. Josefina, J. Chem. Soc., Dalton Trans., No. 3, 733–740 (198) [sic].
J. R. Sutter and W. Spencer, J. Phys. Chem., 94, No. 10, 4116–4119 (1990).
N. M. Émanuél' (ed.), Free Radicals in Biology [Russian translation], Mir, Moscow (1979).