Hydrothermal synthesis and structural characterization of the molybdenum(VI) arsenate (C5H5NH)2(Mo2O5)-(HAsO4)2·H2O

Abstract

A new molybdenum(VI) arsenate, (C₅H₅NH)₂(Mo₂O₅)(HAsO₄)₂·H₂O, has been synthesised hydrothermally at 230 °C and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The compound crystallizes in the triclinic space group P with a= 7.708(1), b= 12.262(3), c= 12.281(4)Å, α= 115.98(2), β= 103.36(2), γ= 98.71 (2)°, Z= 2 and R= 0.0293. The structure is composed of pyridinium cations, water molecules and [(Mo₄O₁₀)(HAsO₄)₄]^4– cluster anions. The anions, which lack Mo–Mo bonds, are linked by strong hydrogen bonds to form layers parallel to the ac plane with pyridinium cations between the layers. Water molecules are within the layers and are linked to both the cluster anions and pyridinium cations through hydrogen bonding.