Charge-transfer Complexes, Gas-liquid Chromatographic and Photochemical Characteristics, and Solvent Adducts of Polyphenylenes and Related Linear Polyphenylsls

Abstract

The absorption spectra of the charge-transfer (CT) complexes formed by two acceptors (tetracyanoethylene and 2,3-dichloro-5,6-dicyano-p-benzoquinone) with thirteen macrocyclic polyphenylenes and with thirty-eight linear polyphenyls were measured in dichloromethane. A linear relationship existing between the first transitions of the CT-complexes and those of the uncomplexed donor hydrocarbons made it possible to predict the CT-bands of new polyphenylenes and polyphenyls. By the gas-liquid chromatography using a glass capillary column, forty-nine polyphenyls and polyphenylenes, containing a large number of isomers, were successfully analyzed. The relationship between the retention times and the structure of linear polyphenyls was expressed by means of a simple empirical equation, and the equation was also applicable to the polyphenylenes by adding a correction factor. These equations are extremely useful for the estimation of the retention time and elution order and the structure of unknown polyphenyls and polyphenylenes. The reductive irradiation of m,m,o,p,o-pentaphenylene provided the bridged annulene compound. For six polyphenylenes and the related compounds, the criteria for the occurrence of the intramolecular photocoupling reaction were discussed. Among the examined polyphenylenes, m,o,o,m,o,o-hexaphenylene and o,p,p,o,p,p,o,p,p-nonaphenylene formed the adducts with several solvents.