Premium
Kinetic and mechanistic study of the copper( II )–oxamate complexation, monitored by the Cu II solid state ion selective electrode
Author(s) -
Karayannis M. I.,
Veltsistas P. G.,
Merkoci A. X.
Publication year - 1995
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140070203
Subject(s) - copper , chemistry , reagent , kinetic energy , reaction rate constant , enthalpy , ion , equilibrium constant , stability constants of complexes , activation energy , steric effects , electrode potential , electrode , electrochemistry , inorganic chemistry , chelation , analytical chemistry (journal) , kinetics , thermodynamics , stereochemistry , chromatography , organic chemistry , physics , quantum mechanics
The complexation process of copper( II ) with oxamates was followed by the use of a copper solid state ion selective electrode. The shape of the recorded potential vs. time was interpreted on the basis of the known kinetic expressions for a two step reaction, monitoring the consumption of the reagent. The potential changes of the electrode are attributed to a decrease in the copper concentration. The curves are of an exponential form with two distinct parts, the first due to the intermediate activated complex, which is produced very rapidly, and the second is due to the slow formation of the soluble chelate. The effects of various parameters are studied in relation to the retardation of the first step. The reaction rate constant k , the equilibrium constant K * for the first step, the stability constant K , the activation energy E a , the change in enthalpy, and the product ( pZ ) of the frequency and steric factors were determined. On the basis of the above data, a mechanistic scheme for this complexation reaction is proposed.