Hydrothermal Synthesis and Structures of Three-Dimensional Zinc Phosphates Built-Up from Two-Dimensional Layers and One-Dimensional Chains and Ladders

Abstract

Three new zinc phosphates, I, [(NH4)(CH3CH2CH2NH3)][Zn3(HPO4)(PO4)2]; II, [NH3(CH2)3NH(CH2)3NH3][Zn3(H2PO4)(HPO4)2(PO4)]·H2O; and III, [NH3(CH2)3NH2(CH2)3NH3][Zn3(HPO4)3(PO4)], have been synthesized in the presence of 1,3,5-triethylhexahydrotriazine (TEHT) and dipropylenetriamine (DPTA), and their structures have been determined by single-crystal X-ray diffraction. The structures consist of vertex-linking ZnO4 and PO4 tetrahedral units forming channels bound by 8-, 10-, and 16-T atoms (T = Zn, P). While the structures of I and II are built up from two-dimensional layers cross-linked by one-dimensional ladders or chains, that of III is built up by cross-linking of ladders. The framework structure of II and III is built up from strictly alternating ZnO4 and PO4 units, and in I, infinite Zn−O−Zn chains are observed, formed by two Zn atoms sharing two three-coordinated oxygen atoms. The amine molecule in I, propylamine, has been obtained by the decomposition of TEHT under hydrothermal conditions. The amine molecules in I−III occupy the channels. Crystal data: I, triclinic, space group = P(−1) (no. 2), M = 559.18, a = 5.0986(6) Å, b = 10.4943(1) Å, c = 12.4457(1) Å, α = 87.614(2)°, β = 87.258(1)°, γ = 89.994(2)°, V = 664.6(1) Å3, R1 = 0.0342, wR2 = 0.091 [1913 observed reflections with I > 2σ(I)]; II, triclinic, space group = P(−1) (no. 2), M = 731.28, a = 8.4821(7) Å, b = 9.1326(8) Å, c = 14.7961(1) Å, α = 90.382(2)°, β = 100.123(2)°, γ = 107.04(1)°, V = 1076.7(1) Å3, R1 = 0.0332, wR2 = 0.0747 [2954 observed reflections with I > 2σ(I)] III, monoclinic, space group = Cc (no. 7), M = 713.26, a = 15.1085(4) Å, b = 8.8403(4) Å, c = 17.2628(6) Å, β = 114.537(2)°, V = 2097.5(1) Å3, R1 = 0.0315, wR2 = 0.0804 [2323 observed reflections with I > 2σ(I)].