Evidence of New Fluorinated Coordination Compounds in the Composition Space Diagram of FeF3/ZnF2–Hamtetraz-HFaq System

Abstract

The exploration of the composition space diagram of the FeF3/ZnF2–Hamtetraz-HFaq system (Hamtetraz = 5-aminotetrazole) by solvothermal synthesis at 160 °C for 72 h in dimethylformamide (DMF) has evidenced five new hybrid fluorides (1–5); the structures are characterized from single crystal X-ray diffraction data. [Hdma]·(ZnFeIII(H2O)4F6) (1) and [Hdma]·[Hgua]2·(FeIIIF6) (2) contain anionic inorganic chains (1) or isolated octahedra (2) weakly hydrogen bonded (Class I hybrids) to dimethylammonium (Hdma) and/or guanidinium (Hgua) cations which are produced from the tetrazole ligand and solvent decomposition. [Hdma]2·[Hgua]·[NH4]·[ZnFeIIIF5(amtetraz)2]2 (3), [Hdma]2·[Zn1.6FeII0.4FeIIIF6(amtetraz)3] (4), and [Hdma]·[Zn4F5(amtetraz)4] (5) are considered as Class II hybrids in which the (amtetraz)− anions are strongly linked to divalent metal cations via N–M bonds. In 3, ∞{[NH4]·[ZnFeIIIF5(amtetraz)2]2} layers are separated by [Hdma]+ and [Hgua]+ cations. 4 and 5 exhibit three-dimensional (3D) hybrid networks that contain small cavities where [Hdma]+ cations are inserted. A porous 3D metal–organic framework intermediate is evidenced from the thermogravimetric analysis and X-ray thermodiffraction of 5.