Structure and phase transitions in tetramethylammonium pentachloroindate(III) crystals

Abstract

Differential scanning calorimetry, dielectric, thermal expansion and X-ray diffraction studies on [N(CH3)4]8[In(HOEt)Cl5]3[In(H2O)Cl5] are reported. The crystal reveals a complex sequence of phase transitions of first-order type. The values of the transitions entropies suggest the “order–disorder” character of the phase transitions. The reorientational motions of the tetramethylammonium cations are expected to contribute to the mechanism of phase transitions in the tetramethylammonium salts studied.