Cyclopentadienyl Dicarbonyl Iron‐Bismuth Compounds – Synthesis,Structure, and Reactivity

Abstract. The cyclopentadienyl‐substituted iron‐bismuth complexes {Cp(CO)₂Fe}BiCl₂] ( 1 ), {Cp(CO)₂Fe}BiBr₂] ( 2 ), {Cp′′(CO)₂Fe}BiBr₂] ( 3 ) and {Cp*(CO)₂Fe}BiBr₂] ( 4 ) were prepared with high yields starting from Cp^x(CO)₂Fe]₂ Cp^x = C₅H₅ (Cp), C₅H₃‐1, 3‐tBu₂ (Cp′′), C₅Me₅ (Cp*)] and the corresponding bismuth halides. The single crystal X‐ray structure analyses of compounds 2 – 4 are reported. Comparison of their solubility demonstrates that the steric hindrance in this type of compounds is only slightly higher for compound 3 compared with compound 2 but significantly lower compared with the Cp* derivative 4 . Compounds 1 – 4 react with nucleophililic reagents such as KOtBu, NaOCH₂CH₂OCH₃, and NaOSiMe₃ as well as with water in the presence of an amine to give a mixture of {Cp^x(CO)₂Fe}BiX] (X = Cl, Br) and {Cp^x(CO)₂Fe}₃Bi]. In case of a reaction with nBu₄NCl and DMAP (dimethylaminopyridine) no such dismutation is observed. Instead the complexes {Cp(CO)₂Fe}BiBr₂(DMAP)₂] ( 5 ), NnBu₄]₂{{Cp(CO)₂Fe}BiBr₃}₂] ( 6 ) and NnBu₄]₂{{Cp(CO)₂Fe}BiCl₃}₂] ( 7 ) were isolated and characterized by single‐crystal X‐ray diffraction.