Formamidinhim-Hexachloroferrat(III) Synthese und Kristallstruktur / Formamidinium-Hexachloroferrate(III) Synthesis and Crystal Structure

Abstract

[HC(NH 2 ) 2 ] 3 FeCl 6 was obtained together with other products from the reaction of S 4 N 4 with HCl in H 2 CCl 2 in the presence of FeCl 3 . Its crystal structure was determined from X-ray diffraction data (473 independent observed reflexions, R = 0.047). Lattice constants: a = 961.6, c = 876.4 pm; tetragonal, space group P4 2 /m, Z = 2. Of the two crystallographically independent formamidinium ions HC(NH 2 ) 2 ⊕ , one exhibits positional disorder; the other one has C-N bond lengths of 128 pm. The FeCl 6 3⊖ ions have symmetry C2h, but the deviation from Oh is small.