Synthesis and characterization of a novel microporous indiumphosphate

A microporous indiumphosphate has been synthesized for the first time from the hydrothermal reaction of H 3 PO 4 , In 2 O 3 and H 2 O in the presence of one of the following templates, tfiethylamine (Et 3 N), n-butylamine (n-BuA), dimethylamine (DMA), dipropylamine (DPA), ethylenediamine (EDA), or tetramethylammonium hydroxide (TMAOH). Single crystal x-ray diffraction structural analysis demonstrates that the crystal crystallizes in orthorhombic symmetry, space group Pbca. One asymmetric unit consists of InPP 4 (H 2 O) 2 in composition. The 3D microporous structure contains 6- and 4-ring un-intersected parallel channels running along the 2>-axis. In and P atoms appear in a strict alternative order bridged through O atoms forming the octahedral and tetrahedral geometry respectively. Among the six O ligands of the In, four are framework 0 atoms and the other two are water oxygens. The P atoms are exclusively coordinated to framework O atoms. XRD, FT-IR and TG studies demonstrate that the microporous indiumphosphate is unstable to thermal treatment above 330°C which is believed to be the consequence of removal of structural water molecules.