Activation volumes (ΔV‡) for the complexation of the iron(III) ion with thiocyanate (SCN-) and acetohydroxamic acid (Hahx) were determined by a high-pressure stopped-flow technique. The values of ΔV‡ for reaction of Fe3+ are -6.1 - 1.0 cm3 mol″1 for SCN- and -10.0 - 1.4 cm3 mol-1 for Hahx, whereas the ΔV‡ values of the FeOH2+ ion are 8.5 -1.2 cm3 mol″1 for SCN- and 7.7 - 0.6 cm3 mol-1 for Hahx. Complexation of FeOH2+ is dissociatively activated but that of Fe associatively. No apparent parallel relationship is observed between ΔV‡ and corresponding AS values.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry