Interaction of Ni(II), Co(II) and Cu(II) with <img src='http://www.niscair.res.in/jinfo/smaller.gif' border=0><img src='http://www.niscair.res.in/jinfo/small.gif' border=0>-aminobutanedioic acid - A kinetic approach

Abstract

Comprehensive kinetic study on the interaction of Ni(II), Co(Il) and Cu(II) with DL-aminobutane-dioic acid has been carried out in the <i>p</i>H range 6.00-7.13 for Ni(II) and Co(II) and 2.11-3.11 for Cu(II) in 0.1<i>M </i>KNO₃ at different temperatures 25-40 (± 0.05°C) using stopped-flow spectrophotometer. The complexation reactions have been discussed in terms of Eigen mechanism in which the loss of water molecule from the metal ion in the ion pair is an important rate determining step. Experimental rate constants have been resolved into stepwise rate constants and the activation parameters corresponding to different binding steps have been evaluated. The determined values of <i>k</i>_o (the rate constant for exchange of water molecule) compare well with the expected values as determined by NMR studies.