Syntheses, structures and comparative electrochemical study of π-acetylene complexes of cobalt

The preparation and characterization of the complexes [Co2(CO)4(μ-dppm)]2(μ-η2-Me3SiC2(CC)2C2H) (2), [Co2(CO)4(μ-dppm)]2(μ-η2-HC2(CC)2C2H) (3), Co2(CO)4(μ-dmpm)(μ-η2-Me3SiC2CCSiMe3) (4), Co2(CO)4(μ-dmpm)(μ-η2-Me3SiC2CCH) (5), [Co2(CO)4(μ-dmpm)]2(μ-η2-Me3SiC2(CC)2C2SiMe3) (6) and [Co2(CO)4(μ-dmpm)]2(μ-η2-HC2(CC)2C2H) (7) are described. A comparative electrochemical study of all these complexes and the related [Co2(CO)4(μ-dppm)]2(μ-η2-Me3SiC2(CC)2C2SiMe3) (1), Co2(CO)4(μ-dppm)(μ-η2-Me3SiC2CCH) and Co2(CO)4(μ-dppm)(μ-η2-HC2CCH) is presented by means of the cyclic and square-wave voltammetry techniques. Crystals of 2 and 3 suitable for single-crystal X-ray diffraction were grown and the molecular structures of these compounds are discussed.

Graphical abstractNew butadiyne and octatetrayne complexes containing one or two Co2(CO)4(X) units (X = dppm, dmpm) have been prepared and characterized. Electronic communication in the bis(dinuclear) compounds has been proven by electrochemical (the cyclic and square-wave voltammetry) means. A comparative electrochemical study is presented.Figure optionsDownload full-size imageDownload as PowerPoint slide