Neue FeAsS-Kaefigstrukturen aus +Fe(CO)2>2 (Cp+ = C5Me4Et) und Realgar

Article abstract of DOI:10.1016/0022-328X(94)88115-4

The reaction of +Fe(CO)2>2 (Cp⁺ = η⁵-C5Me4Et) with equimolar amounts of As4S4 in boiling toluene gives Cp⁺2Fe2As2S2 (1) and Cp⁺2Fe2As2S3 (2).Both complexes form with two equivalents of Cr(CO)5THF the bisadducts Cp⁺2Fe2As2S2*2Cr(CO)5 (3) and Cp⁺2Fe2As2S3*2Cr(CO)5 (4), respectively.The Cr(CO)5 fragments are bound to the As atoms.X-ray diffraction analyses have been carried out for 1 and 4.The structure of 1 contains two coplanar η²-AsS bridges which bisect the Fe-Fe vector and are parallel to the Cp⁺ ligands.Complex 1 is formulated as a 30e tripledecker complex for it contains an As-As distance (2.629(1) Angstroem) very close to As-As bonding.The structure of 4 contains a Fe2As2S3 cage.The inorganic ligand is formally built up by two syn oriented AsS units which are bridged by a S atom.Such a view is supported by the conversion of 1 into 2 by reaction with a mild sulfur donator, e.g.As4S4.Key words: Chromium; Iron; Carbonyl; Arsenic, Sulfur; Cage compound