Reaktionen an komplexgebundenen Liganden, XXII Synthese und Reaktionen von Cyclopentadienyl-diphosphan-carbonyl-Eisen- und Chrom-Komplexen / Reactions at Complex Bonded Ligands, XXII Synthesis and Reactions of Cyclopentadienyl Diphosphane Carbonyl Iron and Chromium Complexes

Abstract

The synthesis of binuclear iron and chromium complexes with bridging dppe ligands is reported, e.g. [μ-dppe{C5H5Fe(CO)Br}2] or [μ-dppe{C5H5Cr(CO)(NO)}2], (dppe = (C6H5)2PC2H4P(C6H5)2). With hydrazine, these compounds yield no doubly bridged complexes with dppe and N2H4 bridges, neither in dark- nor in photo-reactions. In case of the iron complexes either reduction of the starting complex or transformation of the dppe bridging ligand into a chelating ligand are observed instead. The reactions depend upon the polarity of the solvent and yield [μ-dppe{C5H5Fe(CO)}2] in benzene, however, [C5H5Fe(CO)(dppe)]Br in tetrahydrofuran. The chromium complex undergoes decomposition on UV irradiation, splitting off CO and yielding the chelate complex [C5H5Cr(NO)(dppe)] as well as polymeric [C5H5Cr(NO)]x.