Vibrational spectra of Te(OH)6.2NH4H2AsO4 and Te(OH)6.2(NH4)2HAsO4

IR and Raman spectra of Te(OH)₆.2NH₄H₂AsO₄.(NH₄)₂HAsO₄ (compound I) and Te(OH)₆.2(NH₄)₂HAsO₄ (compound II) are recorded and analysed. The symmetry of different groups and the vibrational interaction between them are discussed. The observed spectra suggest the existence of HAsO²⁻₄ in II and coexistence of HAsO²⁻₄ and H₂AsO⁻₄ in I. The ammonium ion is found to execute hindered rotation in the lattice in both the compounds.     

The crystal structure of potassium ammonium hexamolybdotellurate with telluric acid K5NH4[TeMo6O24].Te(OH)6.6H2O

An inorganic compound formulated as K₅NH₄[TeMo₆O₂₄].Te(OH)₆.6H₂O (1) has been isolated by conventional solution method and structurally characterized by single-crystal X-ray diffraction methods, scanning electron microscopy (SEM), IR, UV–vis spectra, and cyclic voltammetry measurements. This compound crystallizes in the monoclinic system, space group C2/c with unit a = 18.6841(1) Å, b = 10.0513(1) Å, c = 21.1065(1) Å, β = 116.495(1)°, V = 3547.49(4) ų, Z = 4, R = 0.033 and wR (F²) = 0.087 for 3432 unique observed reflexions [I > 2σ(I)]. The crystal structure of (1) is built up from an Anderson clusters connected through hydrogen-bonding interactions into a three-dimensional supramolecular network.