A METAL-RICH FLUORINATED INDIUM PHOSPHATE, TER-DOT[IN-9(PO4)6(HPO4)(2)F-16]CENTER-DOT-3H(2)O, WITH 14-MEMBERED RING CHANNELS

The organically templated 3-D open-framework metal-rich phosphate 4[NH 3(CH2)(3)NH3]. 3[H3O].[In-9(PO4)(6)(HPO4)(2)F-16]. 3[H2O] has been syn thesized hydrothermally and its structure determined by single-crystal X-ray diffraction. The compound is monoclinic, P2(1)/n, a 13.616(2) A ngstrom, b = 9.372(2) Angstrom, c = 23.293(4) Angstrom, beta = 99.44(2 )degrees, V = 2932.1(9) Angstrom(3), R = 0.034, R-w = 0.038. It was ch aracterized further using TGA, P-31 NMR, and elemental analysis, which supported the above formulation. The compound has a complex system of channels, which feature large elliptical 6.5 x 14 Angstrom cavities r esulting from 14-membered rings. An unusually high degree of fluorinat ion is found for this compound resulting from use of 8 molar equivs of HF in its preparation. The fluorides occupy both terminal and bridgin g environments around the indium. The former are involved in hydrogen bonding to countercations, and the latter are critical to corner shari ng of In octahedra to create In-3 polyhedral subunits. The anion frame work can be described in terms of a pillared layer structure in which corrugated sheets of formula [In-9(PO4)(6)F-16](7-) are pillared via t he (HPO4)(2-) groups.