Perfluoro-1,3-butadiene, dimerization

Irradiation of the anti-dimer of perfluorotetramethylcyclobutadiene in a fluorocarbon solvent affords a mixture of perfluoro-octamethylcubane and perfluoro-octamethylcuneane the intermediacy of the butadiene syn-dimer and of perfluoro-octamethylcyclo-octatetraene is proposed. Hydrogenolysis of the 4-substituted homocubanes (752 X = Br, Y = Cl, Br, COjH, CH2OH, or COjMe) over various... 

At 200°C, perfluoro-1,3-butadiene dimerizes. What is the structure of the dimer ... 

Cycloadditions of fluorinated dienes are known to give cyclobutane rings. The original suggestion of the structure of the dimer of perfluoro-1,3-butadiene was perfluorotricyclo[4,2,0,02 5]octane [727]. The compound did not react with potassium permanganate. Fifteen years later, another formula was found correct based on physical methods. Instead of three four-membered rings, the product consists of three five-membered rings. Its name is perfluorotricyclo[3,3,0,02 6]octane [128],... 

---