The Determination of Molecular Quantities from Measurements on Macroscopic Systems.III. Electro-optical Absorption Measurements on Michler's Ketone

Abstract

Abstract Some bulk quantities appropriate for the description of electro-optical absorption measurements on macroscopic systems are defined and their properties are discussed. Based on three molecular models (Lorentz model, Onsager model in spherical approximation and in ellipsoidal approximation) model molar quantities are introduced, which depend on intrinsic properties of the molecule (dipole moments and polarizabilities in the ground and excited state, transition dipole moment and transition polarizability). The relations will be applied for the evaluation of the results of electro-optical absorption measurements on Michler's ketone in cyclohexane in a wavenumber interval near 30 · 105 m-1 . The angles between the dipole moments in the ground and the excited state and the transition dipole moment will be determined; the magnitude of the dipole moment in the corresponding excited state is μaG = 30 · 10-30 Cm. The data show that the symmetry of a solute Michler's ketone molecule most probably corresponds, at least approximately, to the pointgroup Cs.