Structural, thermal behavior and vibrational studies of the new rubidium arsenate tellurate Rb2HAsO4•Te(OH)6

Crystal structure of Rb2HAsO4 center dot Te(OH)(6) crystallizes in the monoclinic system space group P2(1)/c. The unit cell parameters are a = 8.344(2) angstrom, b = 7.12(10) angstrom, c = 12.453(2) angstrom and beta = 90.28(1)degrees. The main feature of this atomic arrangement is the coexistence of two independent and different anions (AsO34- and TeO66-) in the unit cell, connected by hydrogen bonds (O-H center dot center dot center dot O) which make the building of the crystal. The arrangement of different polyhedral in the structure forming tunnels where cations Rb+ are placed. The Raman and IR spectra recorded at room temperature, in the frequency ranges (50-1300) cm(-1) and (4000-400) cm(-1), respectively, confirm the presence of AsO43- and TeO66- groups and elucidate the hydrogen bonds in their crystal lattice. The thermal analysis ((DTA) and (TG)) of the title compound show that the decomposition of this material start at a temperature equal to 500 K and the differential scanning calorimetry (DSC) analysis shows three phase transitions at 332 K, 464 K and 476 K. (C) 2012 Elsevier B.V. All rights reserved.