15min:
MEASUREMENT OF EXCITED STATE DIPOLE MOMENTS OF 7-AZAINDOLE IN THE GAS PHASE..

CHEOLHWA KANG, JOHN T. YI AND DAVID W. PRATT, Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260.

The rotationally resolved S1 leftarrow S0 fluorescence excitation spectrum of 7-azaindole has been obtained in the presence of an external electric field. The Stark effect on the rotational energy levels allows us to accurately determine the values for each component of the dipole moment in both electronic states. The magnitudes of dipole moment components are µa (S0) = 1.45 \pm 0.01 D, µb (S0) = 0.65 \pm 0.06 D and µa (S1) = 2.23 \pm 0.01 D, µb (S1) = 0.55 \pm 0.07 D. The large increase in µa is a result of changes in the electron distribution in the S1 state. A detailed discussion of these changes will be given.