Hydro(solvo)thermal synthesis and structural characterization of a new organically templated gallophosphate: [H 3N(CH 2) 2NH 3] 1/2·[Ga 5 (PO 4) 4(OH) 4

Abstract

A new three-dimensional open-framework gallophosphate: [H 3N(CH 2) 2NH 3] 1/2·[Ga 5 (PO 4) 4(OH) 4] has been prepared by hydro(solvo)thermal synthesis in presence of ethylenediamine (en) as structure-directing agent. Its structure was determined by means of single-crystal X-ray diffraction analysis with the following crystal data: monoclinic space group C2 /m, a=10.1604(9) Å, b=12.0085(15) Å, c=7.1892(7) Å, β=90.797(6)°, V=877.08(16) Å 3, Z = 2 , R 1 = 0.0264 , w R 2 = 0.0764 . The total numbers of measured reflections and unique reflections were 3508 and 1300, respectively. It is built up from a new secondary building unit (SBU) Ga 4P 4O 20(OH) 4, in which Ga atoms exhibit distorted trigonal bipyramidal coordination and P atoms are in tetrahedral coordination. The SBU Ga 4P 4O 20(OH) 4 are linked into a layer by bridge oxygen atoms. The GaO 4(OH) 2 octahedra link the layers into a three-dimentional framework. Diprotonated ethylenediamine was found in the channel of the framework. The material was characterized by IR spectroscopy, 1H NMR spectra, thermogravimetric and differential thermal analyses and elemental analysis.