Arene synthesis by extrusion reaction. 12 Chemistry of dibenzo[2.2]paracyclophane and its related compounds. Evidence for the existence of a cyclophyne intermediate
respectively. The IR and UV/Vis spectra are compared with p-xylylene and the benzylradical as models for a quinoid or diradicaloid structure. The absence of an ESR signal reveals a singlet ground state for these compounds. Remarkable is a sharp absorption in the red part of the visiblespectrum which is not observed in the case of p-xylylene or the benzylradical. The electronic structure can be