Further evidence of the efficiency of the fluoride route illustrated by the hydrothermal synthesis and crystal structure of the hydroxyfluorogallophosphate Mu-20

In the present paper, the synthesis and structure determination of a new th ree-dimensional microporous hydroxyfluorogallophosphate, denoted Mu-20, is reported. This material was obtained by hydrothermal synthesis in the prese nce of ethylenediamine as organic template, using the fluoride route. Its s tructure was determined by single crystal X-ray diffraction. The symmetry i s tetragonal, space group P4(2)/ncm, with the following unit-cell parameter s: a=b=10.043(7) Angstrom and c=13.828(10) Angstrom. The three-dimensional framework of Mu-20 is completely built from chains ob tained by connection of four-membered rings (4 MR) which consist of 2 Ga an d 2 P atoms. In these 4 MR, the two gallium atoms are bridged by a fluorine atom. The resulting framework displays two channel systems delimited by no n-planar 7 and 8 MR openings, in the a and c direction, respectively. The p rotonated amine is disordered inside the pores. This material was character ized by elemental and thermal analyses, XRD, SEM and C-13, F-19 and P-31 so lid state NMR spectroscopy.