CRYSTAL-STRUCTURE AND SOLID-STATE NUCLEAR-MAGNETIC-RESONANCE CHARACTERIZATION OF AN OXYFLUORINATED 3-DIMENSIONAL FRAMEWORK GALLOPHOSPHATE WITH ULM-4 STRUCTURAL TYPE - STRUCTURAL RELATIONSHIPS WITH GAASO4-2

Ga-3(PO4)(3)F-2, 0.75 H3N(CH2)(3)NH3, 0.5 H3O (ULM-4) was obtained by hydrothermal synthesis (453 K, 24 h, autogenous pressure) from a mixtu re of Ga2O3, H3PO4, HF, 1,3-diaminopropane and H2O in the ratio 1:2:2: 1.3:80. The structure was studied by single-crystal X-ray diffraction and solid state NMR. It is monoclinic (space group P2(1)/n (no. 14)) w ith a = 8.674(1) Angstrom, b = 10.190(2) Angstrom, c=16.826(3) Angstro m, beta = 94.21(2)degrees, V = 1483.1(7) Angstrom(3) and Z = 4. The op en framework delimits one-dimensional 10-ring channels; it is built up from the hexameric unit Ga-3(PO4)(3)F-2 in which the gallium atoms ex hibit two types of surrounding. One of the three gallium atoms is octa hedrally coordinated and the two others are in trigonal bipyramidal co ordinations where fluorine atoms link the gallium atoms together. Stro ng hydrogen bonding interactions between the fluorine and the amine fu nctions of the diamines are evidenced. The structure was examined by P -31, F-19, N-15 and C-13 solid-state nuclear magnetic resonance spectr oscopy. Structural relationships with GaAsO4-2 are discussed.