Our research is directed toward the design of catalysts capable of multi-electron transfer required for the development of photosynthetic systems and fuel cells. One of the biggest challenges that chemists face today is the design and synthesis of multi-electron redox mediators that transfer several electrons simultaneously at very close redox potentials. The pursued goal is to enhance the efficiency of the redox mediator, avoiding high-energy pathways that are involved in single-electron reduction. For various reasons, we believe that ethynylferrocene derivatives are interesting and useful for multi-electron transport. A main reason is the ferrocenylacetylenes constitute an interesting class of ferrocene derivatives since they may serve as starting material for the construction of more complex organometallics. Ethynylferrocene has versatile chelate ligands by which transition metals can be brought close to the sandwich iron. A series of complexes containing a metal complex fragment in the central bridge position has been synthesized and studied.