With these previous studies in mind, we calculated the fluorinated version of TPh-CP-TPh. This revealed that the LUMO+2 of TPh-CP-TPh is stabilized upon fluorination of the backbone and becomes the LUMO in the TPh-F6CP-TPh switch (Figure ). These results suggest that although TNaph-CP-TNaph and TAnt-CP-TAnt are not expected to photoswitch, according to our calculations, fluorination of the CP backbone might stabilize the π*-type orbital of the cyclopentene moiety that leads to photocyclization. Indeed, studies have shown that X-F6CP-X with X = TNaph1, TNaph2, TAnt1, TAnt2, TAnt3 photoisomerize to the closed form, while our calculations indicate that the nonfluorinated analogs are not predicted to photocyclize because the excitation is localized on the πconjugated side groups. These nonfluorinated analogs have not been reported.