FEMTOSECOND LASER STUDY OF THE ALIGNMENT OF REACTANT AND PRODUCTS IN THE PHOTOISOMERIZATION REACTIONS OF CIS-STILBENE

Polarized femtosecond laser studies of the products of the photoisomerization of cis-stilbene demonstrate an unexpectedly high degree of alignment between the cis reactant and trans product transition dipoles and an unexpectedly low degree of alignment between the cis reactant and dihydrophenanthrene (DHP) product transition dipoles. These results are consistent with the reaction toward both trans and DHP involving a significant angular displacement of the ethylene bond. Some possible reasons for this displacement are discussed.