Double‐Layered 1,4‐Distyrylbenzene Chromophores–Synthesis, UV and Fluorescene Spectra

Abstract The reaction of 2.2paracyclophane ( 1 ) with liquid bromine affords a 1:1 mixture of only two isomeric products, the pseudo‐para 2 and pseudo‐ortho tetrabromide 3 . The structure of the pseudo‐para isomer 2 has been determined by X‐ray structure analysis. Fourfold palladium‐catalyzed coupling with styrenes and with methyl acrylate converts 2 and 3 into double‐layered derivatives as e.g. 6a, 7a , and 7b , respectively. The molecular structure of 7a has been established by X‐ray structure analysis. The UV and fluorescence spectra of a variety of substituted products are reported and compared with those of the parent chromophors 2,5‐dimethyl‐1,4‐distyrylbenzene ( 16 ) and 2,5‐diethyl‐1,4‐bis(phenylethynyl)benzene ( 17 ), respectively.