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

Abstract

A new layered gallium phosphate Ga10(PO4)2(HPO4)12(OH)5⋅2.5N4C6H20⋅4.5H2O 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 (no 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.