In this paper, the potential that organometallic architectures consisting of two transition metal centers linked by an organic unsaturated spacer present for the study and development of new molecular wires is discussed. After a bibliographical survey of representative existing molecules, emphasis is set on the decisive role of the terminal organometallic capping groups. In this connection, the very rich redox chemistry of the (dppe)Cp*Fe unit in mononuclear complexes is subsequently developed. Finally, the syntheses and studies of diverse organometallic molecular wire models realized in our group and incorporating this fragment are presented and conclusions on the present state of the art are drawn. A review with 352 references.