Kinetics of Dehydration of Lanthanide(III) 2-Amino-4-Chlorobenzoates

Abstract

The 2-amino-4-chlorobenzoates of Y(III), La(III), Pr(III), Sm(III), Gd(III), Dy(III), Tm(III) and Lu(III) were prepared. Their general formula is Ln(C₆H₃NH₂ClCOO)₃·H₂O. X-ray analysis demonstrated that all the prepared complexes are isostructural. This indicates the same mode of coordination of water and organic ligands throughout the whole series of lanthanide(III) 2-amino-4-chlorobenzoates. The dehydrations of the complexes were studied under non-isothermal conditions in air. From the thermogravimetric data on the dehydrations, the kinetic models best fitting the experimental TG curves were selected. These models suggest that the dehydration is governed by diffusion processes. Kinetic parameters such as the activation energy and pre-exponential factor were calculated by means of the differential and integral methods.