Syntheses and molecular structures of new ferrocenylacetylide-bridged binuclear cobalt carbonyl cluster compounds

Abstract

The reaction of ferrocenylacetylide compounds with Co2(CO)8 at room temperature affords four complexes bearing ferrocenyl units with approximately tetrahedral (μ-alkyne)dicobalt moieties [R–(C≡C) n –R′] [Co2(CO)6] n ′ [R = C5H5FeC5H4-C(CH3)2-C5H4FeC5H4, R′ = H, n = 1, n′ = 1 (1); R = C5H5FeC5H4 [ferrocenyl (Fc)], R′ = –CH=CHCl, n = 1, n′ = 1 (2); R = Fc, R′ = Fc, n = 2, n′ = 1 (3), n′ = 2 (4)]. The compounds were characterized by elemental analysis, IR, 1H(13C) NMR, MS and single-crystal X-ray diffraction analysis. The X-ray analyses show that coordination of the carbon–carbon triple bond and the dicobalt unit result in the formation of a Co2C2 tetrahedral core, and the substituents on the acetylenic units show a distortion from linearity that reflects this coordination mode.