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

Title: 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
Creator: de Berg, Kevin; Maeder, Marcel; Clifford, Sarah
Relation: Inorganica Chimica Acta Vol. 445, p. 155-159
Publisher Link: http://dx.doi.org/10.1016/j.ica.2016.02.052
Publisher: Elsevier
Resource Type: journal article
Date: 2016
Description: 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 25 °C and an ionic strength of 0.5 M. Equilibrium constants, K₁ = (98 ± 1)/M^-1 and K₂ = (7 ± 1)M^-1 have been determined and comparisons made with the literature.
Subject: iron thiocyanates; kinetic instability; initial spectrum; stability constants
Identifier: http://hdl.handle.net/1959.13/1347678
Identifier: uon:30096
Identifier: ISSN:0020-1693
Language: eng
Reviewed

		Thumbnail	File	Description	Size	Format