Abstract

The isomerization of stiff–diphenylbutadiene (S–DPB) and the rotational reorientation times, τ_r, for S–DPB and trans–stilbene were measured by picosecond fluorescence and polarization spectroscopy. Values of τ_R were used to calculate the angular velocity correlation frequencies β, using the Hubbard relation. The variation of isomerization rate with β was found to be predicted well by the Kramers-Hubbard fit, thereby finessing questions regarding the validity of the one dimensional Kramers model. The relationship between the torsional and rotational friction is discussed.

© 1986 Optical Society of America