with the outcome of the difunctionalization reaction. We speculated that this ratio of Z/E stereoisomer is closely related to the photostationary state of the generated alkene. These results clearly demonstrate that photoisomerization process occurred and photostationary states of those tetrasubstituted alkenes could be reached and maintained under the standard conditions (Fig. ). The utility of this chemistry was then demonstrated by the gram-scale synthesis of 3ao in moderate 61% yield (Fig. ). Furthermore, preliminary investigations into the optical properties of 3ao and the other three analogs (3bi-3bk) were conducted. The fluorescence spectrum showed that these molecules exhibited emissions peaks at 418 nm, falling within the blue light region (Fig.