Microporous solids have attracted considerable attention owing to optical, catalytic, or sorption properties. 1 The incorporation of metal centers into microporous materials has been extensively studied toward the goal of preparing compounds with the chemical and thermal stability and selectivity of zeolites. 2 Many chemical reactions can be facilitated by transition metal centers such as free-radical chemistry, redox chemistry, and photochemical reactions.The hydrothermal chemistry of uranium has been the subject of attention in recent years [3][4][5][6][7] owing to the potential structural diversity resulting from the high coordination numbers available to U 6+ and the existence of several desirable physical properties. 8 Despite this, few organically templated open-framework uranium materials are known; one phosphate, 4 one oxide, 5b one molybdate, 5c one fluoride, 6c one sulfate, 6i one phosphite, 6r and one silicate. 7 We report the phase-pure synthesis, crystal structure, and thermal stability analysis of the first microporous uranium phosphate fluoride, [N 2 C 6 H 14 ] 2 -[(UO 2 ) 6 (H 2 O) 2 F 2 (PO 4 ) 2 (HPO 4 ) 4 ]‚4H 2 O (MUPF-1). 9,10 Six distinct uranium sites are observed in MUPF-1, each of which is seven-coordinate in a pentagonal bipyramidal geometry. Each uranium(VI) cation is bound to two oxide ligands through short "uranyl" bonds. The [UO 2 ] 2+ bonds exhibit distances ranging between 1.765(8) and 1.795(8) Å, and O-U-O angles that range between 177.5(4) and 179.0(4)°. These values are near to the average reported values. 11 The five equatorial coordination sites around each uranium center differ. U(1), U(2), U(5), and U(6) are each bound to two oxide ligands that are shared between one UO 7 polyhedron and one PO 4 tetrahedron each, and three oxides that are shared between two UO 7 polyhedra and one PO 4 tetrahedron each. The equatorial coordination environment around U(3) and U(4) contains bonds to three oxides that are shared with PO 4 tetrahedra, one water molecule and one fluoride anion. The assignment of bound water molecules and fluoride anions was based upon bond length (2.299(8) and 2.306(8) Å versus 2.490(9) and 2.452(9) Å for U-F and U-O water bonds, respectively) and hydrogen-bonding interactions (see Figure 1), which are aligned along the a axis. Bond valence calculations 12,13 on MUPF-1, using uranium parameters from Burns et al.,11 resulted in values between 5.939 and 6.071 for the uranium centers. Six distinct phosphate sites exist in MUPF-1, each of which resides in the center of one of two types of phosphate tetrahedra. P(1) and P(6) are each bound to four oxide ligands that bridge to uranium centers, while P(2), P(3), P(4), and P(5) are each bound to three bridging and one protonated oxide.Three analogous [U 2 O 12 ] dimers, consisting of two edge-shared UO 7 polyhedra, are observed in MUPF-1.

Key indicatorsSingle-crystal X-ray study T = 150 K Mean '(C±C) = 0.008 A Ê R factor = 0.021 wR factor = 0.054 Data-to-parameter ratio = 13.8For details of how these key indicators were automatically derived from the article, see

Key indicatorsSingle-crystal X-ray study T = 150 K Mean '(C±C) = 0.010 A Ê R factor = 0.025 wR factor = 0.055 Data-to-parameter ratio = 13.0For details of how these key indicators were automatically derived from the article, see

Phosphate Fluoride. -The title compound is synthesized hydrothermally from a mixture of UO2(OAc)2, DABCO, H4P2O7, H2O, and HF (180°C, autoclave, 24 h, 63% yield). As revealed by single crystal XRD, the new microporous material crystallizes in the monoclinic space group P21/n with Z = 4. The structure contains multiple channels that are connected in three dimensions. -(DORAN, M. B.; STUART, C. L.; NORQUIST, A. J.; O'HARE*, D.; Chem.