Hydrothermal syntheses and single-crystal structures of some novel guanidinium-zinc-phosphates

The mild-condition hydrothermal syntheses and single-crystal structures of three new guanidinium zinc phosphates are reported. CN3H6 . Zn-2(HPO4)(2)H2PO4 and (CN3H6)(2) . Zn(HPO4)(2) are built up from three-dimensional Zn/P/O frameworks encapsulating guanidinium cations in 12-ring channel systems. The latter material has the lowest nodal-framework-atom density per unit volume of any open-framework phase characterized so far. (CN3H6)(6) . Zn-2(OH)(PO4)(3) . H2O is a one-dimensional phase with respect to Zn/P/O connectivity and has a unique triply bridged tetrahedral chain connectivity for simple phosphates. Crystal data: CN3H6 . Zn-2(HPO4)(2)H2PO4, M-r = 478.78, monoclinic, space group P2(1) (No. 4), a = 5.1318(4) Angstrom b = 7.8411(7) Angstrom, c = 16.510(1) Angstrom, beta = 90.110(7)degrees, V = 664.36(8) Angstrom(3), Z = 2, R = 2.43%, R-w = 2.67% [2608 observed reflections with I > 3 sigma(I)]. (CN3H6)(2) . Zn(HPO4)(2), M-r = 377.50, orthorhombic, space group Pna2(1) (No. 33), a = 10.447(2) Angstrom, b = 12.349(2) Angstrom, c = 10.225(2) Angstrom, V = 1319.2(5) Angstrom(3), Z = 4, R = 3.26%, R-w = 3.32% [2252 observed reflections with I > 3 sigma(I)]. (CN3H6)(6) . Zn-2(OH)(PO4)(3) . H2O, M-r = 811.17, trigonal, space group R (3) over bar (No. 148), a = 20.016(7) Angstrom, c = 13.955(6) Angstrom, V = 4842(4) Angstrom(3), Z = 6, R = 5.31%, R-w = 5.52% [630 observed reflections with I > 3 sigma(I)].