ULM-18, A FLUORINATED GALLIUM PHOSPHATE WITH PERFORATED LAYERS - XRD AND NMR, STRUCTURE DETERMINATION, AND HF LOCALIZATION IN A D4R

Ga-4(PO4)(5)HF-1.5 N2C6H18-H-20 (or ULM-18) is an oxyfluorinated galli um phosphate obtained by hydrothermal synthesis using N,N,N',N'-tetram ethylethylenediamine as a template. The structure is described in the triclinic space group P-1 (n degrees 2) with a = 8.5264(7) Angstrom b = 9.2512(7) Angstrom, c = 17.870(2) Angstrom, alpha = 101.742(7)degree s, beta = 99.137(7)degrees, gamma = 87.020(6)degrees, V = 1362.3(2) An gstrom(3), and Z = 2. The two-dimensional framework is built up from s heets containing double four-ring units (D4R) connected by PO4 tetrahe dra. Along [010] and [011], 8-ring channels makes the layers hollow. T he D4R units consist of four PO4 tetrahedra, three GaO4F trigonal bipy ramids, and one GaO5 trigonal bipyramid. The D4R structure contains a templating fluorine. F-19 MAS at high speed and Ga-71 DOR lead to eluc idation of their environment. P-31 NMR MAS, RFDR, and double-quanta an alyses are used to assign phosphorus. P-31-{H-1} CPMAS shows that an h ydrogen is inside the D4R unit. Those features together make this buil ding unit a quite unusual D4R conformation. For sake of the rationaliz ation of the framework construction, this D4R is compared to known MPO D4R (M = Al, Ga, Fe, V, Co), and the results of this comparison sugge st a general scheme for proton insertion in the-structure.