Mechanistic information from the effect of pressure on the kinetics of some anation reactions of aquopentaamminecobalt(III), -rhodium(III), and -chromium(III) ions in acidic aqueous solution

Outer sphere complexes as intermediates in coordination chemistry

“…Little agreement was found. Thus Van Eldik et al [25] placed an upper limit of 0.1 M-1 on the equilibrium constant for ion pairing between pentammineaquocobaltate(III) and sulfate ions obtained by kinetic measurements and compared this result with the reported spectroscopic values of 2.9 and 11.2 M -1. The significance of these discrepancies is discussed by Swaddle [5].…”

“…They found a value of 670+10 at 24.5°C and ionic strength 0.0094 M. There were a number of subsequent studies using other anions [24][25][26]. The objective was to compare second sphere coordination equilibrium constants obtained by spectroscopic means with those deduced from kinetic measurements assuming an interchange mechanism for anation reactions.…”