Dehydration and Rehydration Processes in Microporous Rare-Earth Dicarboxylates: A Study by Thermogravimetry, Thermodiffractometry and Optical Spectroscopy

Abstract The recently discovered microporous materials, [ Ln (H 2 O)] 2 [O 2 C(CH 2 ) 2 CO 2 ] 3 ·H 2 O and [ Ln 2 (H 2 O)] 2 [O 2 C(CH 2 ) 3 CO 2 ] 3 ·4H 2 O ( Ln =trivalent rare-earth ion), exhibit a three-dimensional organic–inorganic network with channels containing weakly bonded water molecules. The ability of these compounds to reversibly adsorb and desorb these water molecules in the temperature range 25–100°C has been confirmed using thermo-gravimetry and thermodiffractometry. In addition, the influence of adsorbed water on the lifetime of the 5 D 0 state of Eu 3+ has been studied by optical spectroscopy.