ROTATIONAL COHERENCE SPECTROSCOPY OF 9,9'-BIFLUORENYL - ASSIGNMENT OF EXCITON COMPONENTS

摘要

Polarized time-resolved fluorescence measurements on the two 0(0)(0) components of the exciton doublet of 9,9'-brifuorenyl yielded distinct sets of rotational coherence transients. These measurements allowed assignment of the transition moment vector for the lower-energy exciton component to 'A' symmetry within the point group C-2. Hybrid transients observed for the other component confirmed 'B' symmetry. Also, we find the interannular twist angle between the two fluorene units to be 62 +/- 5 degrees. Parallel behavior of the 1:1 complex of brifuorenyl with water suggests that the water molecule hydrogen-bonds symmetrically to both aromatic components. [References: 22]