Complexation between iron(III) and nicotinamide in aqueous dimethyl sulfoxide

• Published in: Russian journal of coordination chemistry Vol. 35; no. 12; pp. 912 - 915
• Main Authors: Grazhdan, K. V., Gamov, G. A., Dushina, S. V., Sharnin, V. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-12-2009
• Subjects: Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Physical Chemistry; Stability Constant; Nicotinamide; Gibbs Energy; Coordination Chemistry; DMSO
• ISSN: 1070-3284; 1608-3318
• DOI: 10.1134/S1070328409120094

The stability constants of iron(III) complexes with nicotinamide in water-DMSO mixtures (
X
DMSO
= 0–0.75) were determined by potentiometric titration at 25.0 ± 0.1°C and an ionic strength of 0.25 (NaClO
4
). The contributions from the solvation of the reagents to the Gibbs energy of complexation transfer were analyzed. The stabilities of iron(III), copper(II), and silver(I) complexes with nicotinamide were compared. The observed decrease in the stability constants was attributed to the stabilization of iron(III) solvate complexes as the DMSO content increases.