Abstract: Molecular oxygen,as an electron acceptor,can interact with many organic compounds to form contact charge transfer complexes (CCT) which have the maxima absorption at longer wavelengths than that of the original components. In this paper,the UV-Vis spectra of more than 30 CCT formed from oxygen with organic compounds,including ethers,alcohols,amines as well as hydrocarbons,were measured by the comparison method. An empirical equation related to the ionization potentials of the organic compounds and the wavelengths of the maxima absorption of CCT was proposed.

Key words: contact charge transfer complex, contact charge transfer spectra, ionization potentials