Reaction patterns of cyclopentadienylcobalt(I) carbonyl and acetylene derivatives

摘要: Abstract Studies have been made of photochemical and thermal reaction sequences through which bisubstituted acetylenes are transformed in (C5H5)Co-carbonyl systems into cyclobutadiene cyclopentadienone complexes hexasubstituted benzenes. A primary intermediate observed by its IR spectrum low-temperature reactions (C5H5)Co(CO)2 with diphenyl alkynes RCCR is the mixed mononuclear species (C5H5)Co(CO)(RCCR). At room temperature this converted excess alkyne complex (C5H5)Co(R4C4CO). We isolated from these an important binuclear compound(C5H5)2Co2(μ-CO)(RCCR). In presence compound thermally either to or (C5H5)Co, depending on partial pressure CO system. The forms a catalyst for cyclotrimerization 2-butyne. fluxional metallocycle (C5H5)2Co2[(CH3)4C4], formed sodium amalgam reduction (C5H5)Co(CO)I2 2-butyne, true cyclotrimerization.