Electronic interactions in aromatic compounds. Direct electronic interaction between aromatic rings in conjugated and non-conjugated cis-compounds

Abstract

A study of charge transfer equilibria between a series of cis- and trans-4-styrylpyridines and cis- and trans-1-(4-X-phenyl)-2-(4-pyridyl)cyclopropanes with iodine has been carried out in CCl₄. Acidity constants for these heteroaromatic compounds were determined. The results obtained for the two types of measurements show that through-space conjugation, due to overlap of the non-parallel π-orbitals of the two aromatic systems, operated in both cis-systems.