Synthesis of bridging carbyne butterfly Fe/Se cluster complexes via reaction of complex anions [(μ-RSe)(μ-CO)Fe2(CO)6]−: Crystal structure of (μ-EtOC)(μ-p-MeC6H4Se)Fe2(CO)6

A series of bridging carbyne butterfly Fe/Se cluster complexes (μ-EtOC)(μ-RSe)Fe2(CO)6 (2–8: R=p-MeC6H4, m-MeC6H4, o-MeC6H4, α-C10H7, p-MeOC6H4, p-BrC6H4, p-ClC6H4) have been synthesized by in situ reaction of the [Et3NH]+ salts of anions [(μ-RSe)(μ-CO)Fe2(CO)6]− (1) with electrophile Et3OBF4 in benzene at room temperature. Products 2–8 are new and have been characterized by elemental analysis, and IR, 1H- and 13C-NMR spectroscopy, as well as by X-ray diffraction analysis. The 1H- and 13C-NMR spectra indicated that 2–8 in solution consist of two isomers R(a) and R(e), whereas the X-ray diffraction analysis revealed that the single crystal of 2 (R=p-MeC6H4) is composed of one isomer R(a). 2 is the first structurally characterized complex synthesized by reaction of anions 1 with Et3OBF4, which strongly supports the view of anions 1 being O-centered anions in such a type of reactions.