Effect of the synthesis temperature on the dimensionality of hybrid fluorozincates

• Solvothermal synthesis of four new hybrid fluorozincates.
• Increase of the network dimensionality with the synthesis temperature.
• Intermediate phase with unsaturated zinc coordination sites after desolvatation.

A series of new hybrid fluorozincates incorporating 5-aminotetrazole (Hamtetraz) is obtained from a same starting mixture of ZnF2, HF solution and Hamtetraz in acetronitrile at different synthesis temperatures. The structures, determined by single crystal X-ray diffraction, exhibit various networks with dimensionalities that increase as a function of the synthesis temperature. At 120 °C, two phases, ZnF2(H2O)(Hamtetraz) (1) and ZnF2(Hamtetraz)2 (2), coexist and display 1D infinite chains. ∞[ZnN2F2O] chains are built up from ZnN2F3(H2O) octahedra linked by opposite fluorine corners in 1, while ∞[ZnN2F2] chains of edge sharing ZnN2F4 octahedra are found in 2. At 130 °C, dense layers appear in Zn3F5(H2O)2(amtetraz) (3); they result from the condensation of ∞[ZnF3N2] and ∞[ZnF2NO] chains by fluorine corners to form a neutral 2D network. At 140 °C, [NH4]·(Zn4F5(amtetraz)4)·3H2O (4) presents an anionic 3D network containing small cavities in which water molecules and ammonium cations are inserted. The thermal behavior of the coordination polymers 3 and 4 is studied by TGA analysis and X-ray thermodiffraction; an intermediate phase is observed during the decomposition of 4.

This paper presents a series of new hybrid fluorozincates incorporating aminotetrazole linker obtained by changing the synthesis temperature. Their structures exhibit networks with various dimensionalities correlated to the synthesis temperature. The thermal behavior of two phases has been studied by TGA analysis and X-ray thermodiffraction and an intermediate phase is evidenced after desolvatation of one compound.Figure optionsDownload as PowerPoint slide