The Visible Absorption Spectra and Binding Energy of Quinhydrone-Type Molecular Compounds

The absolute intensities of the visible absorption spectra and the binding energies of quinhydrone-type molecular compounds have been determined by the measurements of their absorption intensities in solutions. The visible absorption spectra of these molecular compounds can be explained as the charge-transfer spectra of the π -electrons of quinone and the B compounds. The intensity of these chargetransfer spectra can be calculated roughly by setting up linear combination of the lowest unfilled MO of quinone and the highest filled MO of the B compound, and the results agree qualitatively with the experimentally derived absorption oscillator strengths. This chargetransfer resonance is thought to be the most characteristic part of the intermolecular binding energy in these molecular compounds.