Figure 2.

(a) Chemical structures of the open- and the closed-ring isomers of 1,2-bis(2,5-dimethyl-3-theinyl)perfluorocyclopentene (1a) (b) absorption spectra of the open- (solid line) and the closed-ring (red line) isomers and (c) top- and side-views of the geometrical structures of the open- and closed-ring isomers.