Diferrocenyl molecular "wires", in which two ferrocenes are linked by a conjugated chain, allowing the communication of redox information between the ferrocenes, are a versatile platform on which to investigate notions of molecular conductivity. In this paper, we examine the role of heteroatoms including O, P, S, and Se, as well as C atoms in various oxidation states-separated from the ferrocenes by intervening double bonds which minimize any steric effects. Surprisingly, oxygen is a better electronic mediator than sulfur, a phenomenon we attribute to superior molecular orbital overlap. These fundamental studies on redox coupling will help to guide the design of efficient organic conductors for organic electronics.