A New Approach to the Equilibrium Study of Iron(III) Thiocyanates Which Accounts for the Kinetic Instability of the Complexes Particularly Observable Under High Thiocyanate Concentrations
This article was originally published as:
de Berg, K., Maeder, M., & Clifford S. (2016). A new approach to the equilibrium study of iron(III) thiocyanates which accounts for the kinetic instability of the complexes particularly observable under high thiocyanate concentrations. Inorganica Chimica Acta, 445, 155-159. doi:10.1016/j.ica.2016.02.052
The kinetic instability of iron(III) thiocyanate complexes in aqueous solution, evidenced by the loss of solution colour with time, has made it difficult to determine reliable equilibrium data. A technique, which measures the absorbance of these solutions as a function of time within milliseconds of mixing Fe3+ with SCN- and which extrapolates to an initial spectrum at time zero, has been designed to overcome these difficulties and is described in this paper. Two complexes, Fe(SCN)2+ and Fe(SCN)2+, have been identified upon analysing the absorbance data for thiocyanate concentrations up to 0.25 M at 25oC and an ionic strength of 0.5 M. Equilibrium constants, K1 = and K2 = have been determined and comparisons made with the literature.
de Berg, Kevin C.; Maeder, Marcel; and Clifford, Sarah, "A New Approach to the Equilibrium Study of Iron(III) Thiocyanates Which Accounts for the Kinetic Instability of the Complexes Particularly Observable Under High Thiocyanate Concentrations" (2016). Science and Mathematics Papers and Journal Articles. 79.