Layered Compounds. XXXVII. Syntheses and Properties of Quadruple-layered Metaparacyclophanes

Six quadruple-layered [2.2]metaparacyclophanes have been synthesized by photo-induced desulfurization or the Hofmann elimination method. Their electronic spectra exhibit stronger transannular electronic iteractions than those of the corresponding triple-layered [2.2]metaparacyclophanes and considerable dependence on the bridge substitution mode of the inside ring. The absorption spectra of the charge transfer compleses of a series of layered metaparacyclophanes and tetracyanoethylene have been studied with regard to the donor characters. It is concluded that the electron release from meta to para ring is significant, while the reverse is less effective.