Syntheses, Structures, and Luminescence Properties of Two New Open-framework Zinc Phosphites Based on 1,2,4-Triazole Derivatives

With 1,2,4-triazole derivatives as structure directing agents, two new openframework zinc phosphites, [Zn（atrz）（HPO3）]n（1） and [Zn（dmatrz）（HPO3）]n（2）（atrz = 4-amino-1,2,4-triazole, dmatrz = 4-amino-3,5-dimethyl-1,2,4-triazole） have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder and single-crystal X-ray diffractions. Both compounds are isostructure and crystallize in the P21/c space group of monoclinic system. Compound 1： a = 9.629（1）, b = 7.384（1）, c = 10.274（1） A, β = 110.729（3）°, V = 683.26（2） A^3, Z = 4, Mr = 229.44, Dc = 2.230 g/cm^3, F（000） = 456, S = 1.10, μ = 3.79 mm^（–1）, R = 0.0181 and w R = 0.0466 for 1121 observed reflections（（40） 〉 2s（（40）））. Compound 2： a = 10.786（2）, b = 8.921（1）, c = 9.749（1） A, β = 107.3°, V = 895.6（3） A^3, Z = 4, Mr = 257.49, Dc = 1.910 g/cm^3, F（000） = 520, S = 1.00, μ = 2.90 mm^（–1）, R = 0.018 and wR = 0.051 for 1581 observed reflections（（40） 〉 2s（（40）））. Both compounds are built up into 4.8-net 2D open-frameworks of vertex-linked Zn O4 and HPO3 units（3.57 × 4.53 A^2 for 1 and 4.43 × 5.90 A^2 for 2）. The structures consist of left-, right-handed helical chains that are connected through oxygen atoms to form an undulated 2D sheet stack, which can be topologically regarded as 4.8~2 nets. Solid-state luminescence properties and thermo gravimetric analyses of these two compounds were investigated, respectively.

Hydrothermal Synthesis of a New Zinc Phosphite （CsH7N2）2·[Zn3（HPO3）4] with Intersecting 8- and 12-Ring Channels

Using 4-aminopyridine as the structure-directing agent（SDA）, a new open-framework zinc phosphite, （CsH7N2）2·[Zna（HPO3）4]（ZnHPO-CJ70）, was synthesized under hydrothermal condition. Single-crystal X-ray diffraction analysis reveals that ZnHPO-CJ70 is constructed by the strictly alternating ZnO4 tetrahedra and HPO3 pseudo-pyramids, with their vertexes linked to generate a three-dimensional（3D） open framework with intersecting 8- and 12-ring channels. Further characterizations of ZnHPO-CJ70 were performed by means of X-ray powder diffraction（XRD）, elemental analysis（ICP, CHN）, infrared spectroscopy（IR） and thermogravimetric（TG） analyses. The results of luminescent test shows that ZnI-IPO-CJ70 exhibits strong fluorescence emissions in the solid state at room temperature.

Synthesis and characterization of a new open-framework zinc phosphite (4,4-(C_5H_4N)_2(CH_2)_3)·[Zn_3(HPO_3)_4]

Employing 4,4＇-trimethylenedipyridine as a template, a new two-dimensional zinc phosphite （4,4＇-（CsH4N）2（CH2）3）＂ [Zna（HPO3）4] has been prepared at room temperature and characterized by single-crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction, and thermogravimetric analysis. The compound crystallizes in the monoclinic space group P21/c, with cell parameters, a = 9.3309（19）/k, b = 14.798（3）A, c = 33.637（7）/k, β= 91.11（3）°, V = 4643.8（16） nm3 and Z = 4. The connectivity of the ZnO4 tetrahedra and HPO3 pseudo pyramids results in infinite corner-sharing 4-membered ring chains as second building units which are further linked by Zn-O-P bonds to form a 2-D layer that with interesting 8-membered ring channels along the [100] direction. The diprotonated 4,4＇-trimethylenedipyridine molecules sit in the middle of the layers along the [100] direction and interact with the framework via hydrogen bonds.