Abstract

It is well-known that benzil (diphenylethanedione) has near-skewed form in the ground state, while the structure in the excited singlet state has been attributed to trans-planar geometry. (The terms "skewed" and "planar" used here refer to the dihedral angle between the planes containing the benzoil groups.) This structural change of benzil in solution has been considered to be very fast at room temperature. In this study, we have directly measured the structural change process by means of transient absorption spectroscopy with femtosecond laser. On the basis of the experimental result, we will discuss the factors controlling the change of molecular structure.

© 1990 Optical Society of America