A metal-rich fluorinated indium phosphate, 4[NH3(CH2)3NH3]•3[H3O]•[In9(PO4)6(HPO4)2F16]•3H2O, with 14-membered ring channels

The organically templated 3-D open-framework metal-rich phosphate 4[NH3(CH2)(3)NH3]. 3[H3O].[In-9(PO4)(6)(HPO4)(2)F-16]. 3[H2O] has been synthesized hydrothermally and its structure determined by single-crystal X-ray diffraction. The compound is monoclinic, P2(1)/n, a 13.616(2) Angstrom, 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 characterized 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 resulting from 14-membered rings. An unusually high degree of fluorination is found for this compound resulting from use of 8 molar equivs of HF in its preparation. The fluorides occupy both terminal and bridging environments around the indium. The former are involved in hydrogen bonding to countercations, and the latter are critical to corner sharing of In octahedra to create In-3 polyhedral subunits. The anion framework 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 the (HPO4)(2-) groups.