ELECTRONIC SPECTRA OF ISOMERIC DONOR-ACCEPTOR COMPLEXES.

Author Institution: Department of Chemistry, Memphis State UniversityDetailed analyses of multiple charge-transfer transitions have provided evidence for the formation and probable structures of isomeric $\pi$-molecular complexes. Electronic spectral measurements were obtained for complexes of tetracyanoethylene with a series of polycyclic aromatic hydrocarbons as well as with mono- and di- substituted benzenes. Studies were conducted in a variety of organic solvents, including carbon tetrachloride, chloroform, methylene chloride and 1,2-dichloroethane. Overlapping charge-transfer absorption bands were resolved in terms of a combination Gaussian-Lorentz function. Energies and intensities of the various transitions have been correlated with molecular orbital calculations of the interacting species. The factors contributing to isomeric complex formation and the elucidation of the resulting geometric configurations will be discussed