Synthesis and characterisation of Group 6 metal carbonyl complexes of bis(ferrocenylchalcogeno)propanes: X-ray crystal structures of [Cr(CO)4{FcTe(CH2)3TeFc}], [Mo(CO)4{FcE(CH2)3E′Fc}] (E = E′ = Se; E = Se, E′ = Te; E = E′ = Te), and [W(CO)4{FcTe(CH2)3TeF

The Group 6 metal tetracarbonyl complexes [Cr(CO)4{FcTe(CH2)3TeFc}], [Mo(CO)4{FcE(CH2)3E′Fc}] (E = E′ = Se; E = Se, E′ = Te; E = E′ = Te), and [W(CO)4{FcTe(CH2)3TeFc}] (Fc = [Fe(η5-C5H5)(η5-C5H4)]) have been prepared and fully characterised. Electronic communication between the ferrocenyl groups is observed in the case of [Mo(CO)4{FcSe(CH2)3SeFc}], where the through-bond Fe⋯Fe distance is 13.17 Å, but in the other four complexes the longer through-bond Fe⋯Fe distances (⩾13.56 Å) preclude it.