Synthesis and characterization of tris(η~5-cyclopentadienyl-μ-carbonyliron)-μ_3-nitrosyl cluster:X-ray structure of[(η~5-C_5H_5)(μ-CO)Fe]_3(μ3-NO).C_4H_8O

Tris)(η 5-cyclopentadienyl-μ-carbonyl-iron)-μ3-nitrosyl cluster was obtained from the reaction of cyclopentadienyl dicarbonyliron dimer with nitrogen monoxide in xylene. The cluster was characterized by elemental analyses, IR, MS and 1H NMR. The crystal structure of [(η5-C5H5)(μ-CO)Fe]3(μ3-NO).C4H8O was determined by X-ray diffraction analysis. It crystallizes in the orthorhombic space group Pnma, a=9.053(2), 6=10.545(2), c=22.525(4) A, V=2150.3(7) A3, Z=4,Dc=1.68 g.cm-3; structure solution and refinement based on 1141 reflections with I > 3.0 (I) (MoKa, A=0.71073 A) converged at R=0.0540. The infrared absorption band at 1325 cm-1 of the μ3-NO in the cluster, which is red shifted, shows that μ3-NO is activated.