ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 36, Number 2
JKCSEZ 36(2)
April 20, 1992 

The thermodynamic parameters for the formation of gadolinium benzoate have been determined in the ionic medium of 0.1 M NaClO4 at 25℃ in aqueous solution. The thermodynamic results indicate that the complex is stabilized by the excess entropy effect caused by the dehydration of reacting ions. The especially high stability of Gd(Ⅲ)-benzoate compared to the monodentate ligand complexes might be ascribed to the conjugation effect of the benzene ring in the benzoate ligand. IR spectra show that benzoate anion acts as a bidentate ligand toward Gd3+ to form a chelate ring in solid state. Magnetic susceptibility data of the compound were also obtained and well described by Curie-Weiss law in the temperature range 80∼300K.