Reversible Phase Change of Organic Compounds Based on Photodimerization Reaction and its Practical Application

以菲甲酸和各种官能团为原料，通过酯化反应合成了新的菲类化合物。它们在室温下均为晶相。化合物在熔融状态下的紫外光照射导致了菲部分的光二聚反应。我们发现，在室温下得到的一些菲二聚体为固态无定形相，而另一些二聚体在光照射下为晶相。各种实验分析和计算机模拟表明，固态非晶相的形成机制与光致二聚体中区域异构体的存在及其在熔融状态下的缓慢扩散有关。菲二聚体也发生了热返反应，并返回到相应的单体上，呈现晶相。利用菲类化合物的光二聚反应和热返反应，我们成功地展示了可重写的光调制。

New anthracene compounds were synthesized by esterification from anthracenecarboxylic acid and various functional groups. They showed crystalline phase at room temperature. UV irradiation of the compounds in their molten state resulted in photodimerization of the anthracene moiety. We found that some of the resulting anthracene dimers showed solid-state amorphous phase at room temperature, while the other dimers exhibited crystalline phase during photoirradiation. Various experimental analyses and computer simulation suggested that the mechanism of solid-state amorphous phase formation is associated with the existing of regio-isomers in the photodimers and their slow diffusion in the molten state. The anthracene photodimers also showed thermal back reaction and thus returned to the corresponding monomers showing the crystalline phase. Using the photodimerization and thermal back reaction of the anthracene compounds, we successfully demonstrated rewritable photopatterning.