Syntheses and crystal structures of two new hydrated rubidium zinc phosphates:: RbZn2(HPO4)(H2PO4)•2H2O, a layered phase containing octahedral and tetrahedral zinc centers, and RbZn(HPO4)(H2PO4)•H2O containing one-dimensional chains of 4-rings

The solution-mediated syntheses, single crystal structures, and physical properties (TGA, IR) of RbZn2(HPO4)(2)(H2PO4) . 2H(2)O and RbZn(HPO4)(H2PO4) . H2O are reported. RbZn2(HPO4)(2) (H2PO4) . 2H(2)O is a new noncentrosymmetric layered phase built up from ZnO6, ZnO4, and PO4 polyhedra-sharing vertices as Zn-O-P and Zn-O-Zn bonds. Eleven-coordinate rubidium cations provide interlayer charge compensation for the anionic Zn/P/O/H sheets. RbZn(HPO4)(H2PO4) . H2O is isostructural with NH4Zn(HPO4)(H2PO4) . H2O and consists of infinite chains of tetrahedral it-rings connected by Zn-O-P bonds. Crystal data for RbZn2(HPO4)(2)(H2PO4) . 2H(2)O is: M-r = 541.20, orthorhombic, space group P2(1)2(1)2(1) (No. 19), a = 7.6458(9), b = 9.965(2), c = 15.603(3) Angstrom, V = 1188.8(3) Angstrom(3), Z = 4, R(F) = 3.90%, R-w(F) = 3.91%, (1695 observed reflections with I > 3 sigma(I)). Crystal data for RbZn(HPO4)(H2PO4) . H2O is M-r = 361.83, triclinic, space group P (1) over bar (No. 2), a = 7.712(2), b = 7.9824(7), c = 8.0422(9) Angstrom, alpha = 64.313(7)degrees, beta = 84.90(2)degrees, gamma = 72.364(9)degrees, V = 424.6(2) Angstrom(3), Z = 2, R(F) = 3.97%, R-w(F) = 4.24%, (1794 observed reflections with I > 3 sigma(I)). (C) 1997 Academic Press.