CpCo(CO)2 was first reported in 1954 by Piper, Cotton, and Wilkinson who produced it by the reaction of cobalt carbonyl with cyclopentadiene.
After the discovery of ferrocene in 1951, Todd Reynolds and Geoffrey Wilkinson in 1956 synthesized the uranium metallocene Cp3UCl from sodium cyclopentadienide and uranium tetrachloride as a stable but extremely air-sensitive compound.