The kinetics and oxidation of di-oxo-bridged manganese (III,
IV) complex of (2,2’ bipyridine by thiocyanate ion (SCN-) has been studied in
aqueous acidic medium. The stoichiometric determination expresses a mole ratio
of 1:3. Kinetics study was carried out under pseudo - first order condition and
showed that the rate of reaction was first-order with respect to
[(bipy)2MnIIIO2MnIV(bipy)2]3+ and [SCN-] respectively. The rate of the reaction
was acid dependent as the rate of reaction increased with increase in acid
concentration. It was found to decrease with increase in ionic strength,
suggesting a negative salt effect. This implies that two opposite charges were
in operation during the redox reaction. The addition of added cations and
anions (Mg2+, Ni2+, CH3COO- and NO3-) increased the rate of reaction and
Michaelis-Menten’s plot showed a zero intercept. Based on the results of the spectroscopic studies which indicated no
shift from the maximum absorbance of 683 nm, kinetic evidence from Michaelis–
Menten’s plot with zero intercept and interaction with added cations and
anions, an outer–sphere mechanism has been proposed for the oxidation of
di-oxo-bridged manganese (III, IV) complex of (2,2’ bipyridine) by SCN-.
Author(s) Details:
Patricia Ese Umoru,
Chemistry Department, Faculty of Science, Nigerian Defence Academy,
Kaduna, Nigeria.
Please see the link here: https://stm.bookpi.org/CICMS-V6/article/view/13605
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