Synthesis and some properties of anionic chloranilate complexes of iron(III). Crystal and molecular structure of rubidium and cesium chloranilatoferrates

摘要

New anionic chloranilate complexes of iron(m) Cs[Fe(C6O4Cl2)_2(H2O)_2] ?4H2O (1), Rb[Fe(C6O4Cl2)_2(H2O)_2] ? 4H2O (2), Rb2[Fe(C6O4Cl2)_2(H2O)_2]_2 ? 5H2O (3), Cs3Fe(C6O4Cl2)_3 (4), (Bu4N)Fe(C6O4Cl2)_2 (5), (Bu4N)_4Fe2(C6O4Cl2)_5 (6), and (R4N)_3Fe(C6O4Cl2)_3 (R = Pr (7), Bu (8), C5H_(11) (9)) were synthesized in an aqueous medium. The Mossbauer spectra of the synthesized chloranilatoferrates are characteristic of the high-spin state of Fe~(III) in an octahedral oxygen coordination. The crystal and molecular structures of compounds 1-3 were determined by X-ray diffraction. The complex anions [Fe(C6O4Cl2)_2(H2O)_2]~2_ involved in these compounds are composed of two chelate chloranilate ions and two water molecules trans- (1,2) or cis-coordinated (3) to the iron atom. Since tetraalkylammonium tris(chloranilato)ferrates 7-9 and binuclear complex 6 are soluble in many organic solvents, they are promising precursors for the synthesis of metal-organic coordination polymers. Tetrabutylammonium bis(chlor-anilato)ferrate (Bu4N)Fe(C6O4Cl2)_2 (5) is the first example of the preparation of an anionic chloranilate complex of iron(ni) with a plausible chain structure in an aqueous medium.