Photoreaction of a 2,11-Diaza[3.3]paracyclophane Derivative: Formation of Octahedrane by Photochemical Dimerization of Benzene

Upon photoirradiation at 300 nm, the title diazaparacyclophane (R = COCF3) provided an octahedrane by the photodimerization of its benzene chromophores. This is the first photochemical formation of octahedrane, namely, via the dimerization of benzene. No octahedrane formation was observed for the photolysis of corresponding carbon-bridged paracyclophane. Thus the nitrogen bridges play an important role in the excited state to afford the octahedrane.