KINETICS OF MNBIP(-FORMATION IN AQUEOUS-SOLUTIONS - I(2) COMPLEX)

The formation and dissociation kinetics of the complex MnBip(+2) in aq ueous solution is studied at constant ionic strength 0.3 M and various pH > 6 to involve only the unprotonated ligand 2,2'-bipyridine in the equilibrium. The temperature jump method was used to determine simult aneously the rate constant k(f) of the complex formation and k(d) of i ts dissociation. Their ratio gives the characteristic stability consta nt K-f. This last value was also confirmed by spectrophotometric titra tion. The effect of the ionic strength on the kinetic and thermodynami c parameters was also studied at constant pH 7. Some suggestions on th e reaction mechanism were advanced.