Synthesis of Double and Quadruple Butterfly Fe/E Cluster Complexes via a New Type of Selenium-Centered Anions (μ-RE)(μ-Se-)[Fe2(CO)6]2(μ4-Se) (E = S, Se, Te) Derived from Novel Reaction of [(μ-RE)(μ-CO)[Fe2(CO)6]- with (μ-Se2)Fe2(CO)6. Crystal Structures of μ4-Se-Containing Double Clusters (μ-EtS)(μ-PhCH2Se)[Fe2(CO)6]2(μ4-Se), (μ-p-MeC6H4Se)(μ-MeSe)[Fe2(CO)6]2(μ4-Se), and (μ-p-MeC6H4Te)(μ-MeSe)[Fe2(CO)6]2(μ4-Se) | doi.page