Structural and physico-chemical characteristics of tetraethylammonium tetrachloridoferrate(III)

The crystal structure of tetraethylammonium tetrachloridoferrate(III) was determined. The crystals are hexagonal, space group P6(3) mc, a = 8.198(1) , b = 8.198(1) , c = 13.183(3) , V = 767.3(2) (3), Z = 2. The asymmetric unit of [(C2H5)(4)N][FeCl4] consists of half each of a tetraethylammonium cation and a tetrachloridoferrate(III) anion. Tetrachloridoferrate(III) ion adopts almost ideal tetrahedral geometry. Structural characterization of the compound is supplemented by the results of its magnetic susceptibility measurements and electron paramagnetic resonance (EPR) spectra. Magnetic measurements of a powdered [(C2H5)(4)N][FeCl4] sample gave a negative Weiss constant of -1.57, which suggests antiferromagnetic coupling. The susceptibility curve of [(C2H5)(4)N][FeCl4] against temperature exhibits a maximum, indicating the presence of antiferromagnetic ordering with a Neel temperature of approximately 2.9 K.