Charge-Transfer Complexes of Indenophanes with ?-Acceptors

Article abstract of DOI:10.1007/BF00809148

The charge-transfer (CT) spectra of the ?-complexes formed by a number of ?-acceptors with several indenophanes as well as indene as a model compound have been measured in methylene chloride at 20 deg C.Association constants and transition energies of these complexes as well as ionization potentials of the ?-donors have been determined.The data obtained indicate the existence of transannular electronic interactions in the indenophane nucleus.Furthermore, the pseudo-para- and meta<2.2>indenophane isomers (3 and 4) show a large difference in their ?-base strength.A good linear relationship has been observed between the association constants and λ_max of the long wavelength CT bands for the ?-complexes of these ?-donors with both tetracyanoethylene (TCNE) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ).All CT complexes studied have a 1:1 stoichiometry. - Keywords: Charge-transfer spectra; ?-Complexes; Indenophanes