TETRAHEDRAL-ATOM ZINCOPHOSPHATE STRUCTURES - SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF 2 NOVEL ANIONIC 8-RING FRAMEWORKS CONTAINING CATIONIC 1,4-DIAZABICYCLO[2.2.2]OCTANE GUESTS

The synthesis and structures of two new microporous, anionic zincophosphates whose channels contain cationic organic cations are described. Zn2(HPO4)3.H2N2C6H12 (ZnPO/dab-A) crystallizes in the triclinic space group P1BAR with a = 9.933(2) angstrom, b = 9.966(2) angstrom, c = 9.518(2) angstrom, alpha = 98.022(3)-degrees, beta = 114.805(3)-degrees, gamma = 107.696(3)degrees, V = 775.0 angstrom3 and Z = 2, with R(F) = 3.94% for 3417 observed reflections, according to the criterion l > 3-sigma(l). Zn4(PO4)2(HPO4)2.3H2O.H2N2C6H12 (ZnPO/dab-B) is also centric triclinic, P1BAR, with a = 9.515(2) angstrom, b = 12.297(2) angstrom, c = 9.461(2) angstrom, alpha = 91.030(4)-degrees, beta = 8.658(4)-degrees, gamma = 93.714(4)-degrees, V = 1091.7 angstrom3, Z = 2, with R(F) = 6.38% for 4150 observed reflections [l > 3-sigma(l)]. Both these new phases consist of a three-dimensional network of ZnO4 and PO4 tetrahedra, linked through oxygen vertices, to form two different open structures containing one-dimensional eight-ring channels, occupied by cationic, protonated diazabicyclo[2.2.2]octane, or dabco [(H2N2C6H12)2+] molecules and water. Some of the zinc and phosphorus polyhedra contain 'hanging' OH2 and OH groups: guest-framework and framework-framework hydrogen-bonds are a key structural feature of these new phases. These new phases are briefly compared with other open-framework topologies.