Synthesis of bimetallic iron-chromium and iron-manganese complexes with conjugated benzodithiophene-based spacers

Palladium-catalyzed Sonogashira coupling reactions of an ethynylferrocene complex, [η6-phenylethynyl]tricarbonyl chromium and [η5(1-5)-1-ethynyl-4-methoxycyclohexa-2,4-dienyl]tricarbonyl manganese with a 2-iodobenzodithiophene derivative lead to the formation of mononuclear complexes. Similarly, condensation of the iodo derivative of one of these complexes with the [η6-phenylethynyl]tricarbonyl chromium and [η5(1-5)-1-ethynyl-4-methoxycyclohexa-2,4-dienyl]tricarbonyl manganese complexes affords bimetallic iron-chromium and iron-manganese complexes. Upon hydride abstraction, the manganese derivatives give the corresponding (η6-arene) cations. The structure of the neutral bimetallic iron-manganese complex has been investigated by X-ray diffraction study.