Structural, vibrational and thermal properties of a new inorganic compound: Tl-0.92(NH4)(0.08)(SO4)(0.65)(SeO4)(0.35)Te(OH)(6)

摘要

A new compound thallium ammonium sulfate selenate tellurate: Tl-0.92(NH4)(0.08)(SO4)(0.65)(SeO4)(0.35)Te(OH)(6) (TlNSSeTe) has been synthesized by slow evaporation at room temperature to specify its phase transition temperatures. X-ray diffractometry data revealed crystallization in the monoclinic system with a P2(1)/c space group with these parameters: a=12.336(2) angstrom, b=7.2038(14) angstrom, c=12.017(2) angstrom et =110.631(10)degrees, V=999.4(3) angstrom(3) and Z=4. Three coexisting anions (TeO66-, SO42- and SeO42-) are the main characteristics of these atomic arrangements in the unit cell, related by O-H...O and N-H...O bonds building up the crystal. The cations Tl+ and NH4+ lie at the same positions between these polyhedra. The new synthesized compound has been characterized by using the differential scanning calorimetry (DSC), thermal analysis [differential thermogravimetric analysis (TG), as well as thermodifference analysis (DTA)], FT-IR and Raman spectroscopy techniques. The DSC results demonstrated phase transitions at 384K, 465K and 472K. DTA and TG proved that decomposition takes place in three steps. The vibrational spectroscopy study at room temperature unveiled not only the occurrence and the independence of anionic and cationic groups, but also the importance of the hydrogen bonds.