Communication between Co2(CO)4dppm Units via Polyferrocenylalkyne Linkages

The synthesis and characterization of a family of ethynylbi- and ethynylterferrocenyls, I−Fc 2 C⋮CR, Fc 2 C⋮CR, and Fc 2 (C⋮CR) 2 (R = Fc, SiMe 3 ), I−Fc 3 C⋮CSiMe 3, Fc 3 C⋮CSiMe 3, Fc 3 (C⋮CSiMe 3 ) 2, and their Co 2 (CO) 6 and Co 2 (CO) 4 dppm complexes are described. The structure adopted by Fc 2 {[Co 2 (CO) 4 dppm C 2 SiMe 3 ]} 2 minimizes the steric interactions between the biferrocene and dppm moieties. Electrochemical studies show that identical redox centers ferrocenyl termini, Co 2 (CO) 4 dppm units, or ferrocenyl groups in the core communicate independently with each other.