Gleichgewichtsgeometrie und spektroskopische Eigenschaften des Biphenyls im S0-und S1-Zustand

Equilibrium geometry and spectroscopic properties of biphenyl in the S₀ and S₁ state Equilibrium geometries for the S₀ and S₁ state of biphenyl were determined by minimization of the total energy with respect to all cartesian coordinates. The molecule is twisted in the S₀ state (20°), but becomes planar in the S₁ state. Using these results, an interpretation of the fluorescence and absorption spectra can be given. In passing from the S₀ to the S₁ state equilibrium geometry a remarkable change of the state ordering occurs.