Synthesis and structural characterization of a new layered gallium phosphate using triethylenetetramine as structure-directing agent

A new layered gallium phosphate Ga₁₀(PO₄)₂(HPO₄)₁₂(OH)₅2.5N₄C₆H₂₀4.5H₂O was hydrothermally synthesized at 180 °C for 3 days by using triethylenetetramine (teta) as structure-directing agent. Its structure was determined by single-crystal X-ray diffraction with a triclinic cell in the space group P-1 (n^o 2) with a=8.4718(1) Å, b=18.5915(1) Å, c=24.1994(3) Å, α=110.538(1)°, β=93.656(1)°, γ=93.549(1)° and V=3547.45(6) Å³. It consists of [Ga₁₀(PO₄)₂(HPO₄)₁₂(OH)₅]⁵⁻ macroanionic sheets composed of infinite chains of GaO₄(OH)₂ octahedra connected via corner-sharing to PO₄ and GaO₄ tetrahedra. They contain four-, seven- and nine-membered rings. The inorganic layers are held together through hydrogen bond between the terminal PO bondings, the water molecules and the terminal ammonium groups of the intercalated teta molecules.