Thermal properties and ion mobility in the antimony(III) fluoride complexes with DL–valine (C5H12NO2)SbF4·H2O and DL–serine (C3H8NO3)Sb2F7. Crystal structure of (C5H12NO2)SbF4·H2O compound

Abstract

Fluoride complexes of antimony(III) with amino acids (DL–valine and DL–serine) of the compositions (C5H12NO2)SbF4·H2O (I) and (C3H8NO3)Sb2F7 (II) have been synthesized. The crystal structure of the (C5H12NO2)SbF4·H2O compound (monoclinic syngony, Z = 4, space group P21/c) has been determined for the first time. The structure of I is composed of cations of DL-valinium ((C5H12NO2)+), complex [SbF4]nn– anions having a polymeric chain structure, and crystallization water molecules. Thermal properties and ionic mobility in fluoroantimonates I and II were studied by the DSC and NMR (1H, 19F) methods. It has been established that irreversible endo-effects on DSC curves at 351 and 385 K for the compounds I and II, respectively, are related to formation of X-ray-amorphous phases. In the complex I, ionic mobilities in fluoride and proton sublattices with frequencies above 104 Hz are absent in the studied temperature range (150–420 K), whereas the ions diffusion is observed in both sublattices of II at 320 K. The mechanisms of emergence of ions diffusion in sublattices of the compound II were suggested.