Reactions of some conjugated diynes with cobalt carbonyl compounds

Abstract

Treatment of dodecacarbonyltetracobalt with the conjugated diynes RC≡CC≡CR (R = CH₃, C₆H₅) yields complexes of stoicheiometry [Co₂(CO)₆]₂- (RC₂C₂R). The same complexes are obtained from octacarbonyldicobalt and the appropriate diyne.     A similar type of complex was obtained from para-(C₆H₅C₂)₂C₆H₄ and Co₄(CO)₁₂. Surprisingly, this complex was not isolated on reaction of the diyne with Co₂(CO)₈.     The infrared, nuclear magnetic resonance, and mass spectra of the complexes are given, and the probable structures of the compounds are deduced from these spectroscopic properties.