The reaction of new ferrocenylacetylene HCC(C 5 H 5 FeC 5 H 3 )C(CH 3 ) 2 Fc′CCH (1; Fc′=C 5 H 4 FeC 5 H 4 ) with Co 2 (CO) 8 has been studied and the spectra and molecular structure of complexes [HCC(C 5 H 5 FeC 5 H 3 )C(CH 3 ) 2 Fc′CCH][Co 2 (CO) 6 ] n [n=1, (4); n=2, (5)] have been determined. Novel complex [FcC(CH 3 ) 2 Fc′CHC]FeCo 2 (CO) 9 (6; Fc=C 5 H 5 FeC 5 H 4 ) has been synthesized by using a nuclear expanding reaction of complex [FcC(CH 3 ) 2 Fc′CCH]Co 2 (CO) 6 (3) with Fe 2 (CO) 9 and the structural characterization of complex 6 was accomplished by elemental analysis, IR, 1 H, 13 C NMR and MS. The electrochemical properties of the compounds with ferrocenylacetylene reveal that there is significant electronic communication between the ferrocenyl groups.