Structure of triaquaoxonium tetrachloroferrate(III) at 215 K by X-ray diffraction

[H9O4]+.[FeCl4]-, structure determined from single-crystal X-ray diffractometer data collected at 215 K. Mr=270.73, monoclinic, P21/c, a=6.355(1), b=11.738(2), c=13.004(2) A, β=97.03(1)0, V=962.8(5) A3, Z=4, Dx=1.87(1) Mg m-3, Mo Kα, λ=0.71073 A, μ=2.64 mm-1, F(000)=540. Refinement based on F2 including 1932 reflextions gave a final R(F) of 0.020. The structure consists of H9O4+ ions and tetrahedral FeCl4- ions. The central oxonium ion in the H9O4+ complex is disordered. The H9O4+ ions form a hydrogen-bonded two-dimensional three-coordinated network paralle to the ab plane. Each water molecule also forms hydrogen bonds with the Cl ions. (orig.)