Stability of Shielded Pentacenes under Ambient Conditions [data]

The stabilization of pentacene through variation of substituents serves as a test bed to access stable organic semiconductors, transferable to the larger soluble acenes and azaacenes. Pentacene is stable enough for derivatization via wet-chemistry but sufficiently labile to test its (induced) (photo)decomposition. In this article, we describe the synthesis of shielded pentacenes, either via covalent jacketing with ester macrocycles or via steric shielding with biphenylyl substituents, together with attempts to access a bis(ortho-quaterphenyl) substituted Geländer pentacene. The photostability of the pentacenes is assessed under ambient conditions (air, light) to simulate handling under typical laboratory conditions and put into perspective with reference compounds, such as TIPS-ethynylated, ether-jacketed or our previously reported Geländer pentacenes.

通过取代基修饰实现并五苯（pentacene）的稳定化，可作为制备稳定有机半导体（organic semiconductors）的研究模型，该策略可拓展应用于更大分子量的可溶性并苯类（soluble acenes）及氮杂并苯类（azaacenes）化合物。并五苯既能满足湿化学法（wet-chemistry）衍生化所需的稳定性要求，又具备足够的反应活性以开展其（诱导）（光）分解过程的测试。本文报道了两类屏蔽型并五苯的合成方法：一是通过酯基大环（ester macrocycles）进行共价包覆，二是借助联苯基（biphenylyl）取代基实现空间位阻屏蔽（steric shielding）；同时还尝试合成了双（邻-四联苯基（ortho-quaterphenyl））取代的Geländer型并五苯（Geländer pentacene）。本文在空气、光照的环境条件下评估了各屏蔽型并五苯的光稳定性（photostability），以模拟典型实验室环境下的实际操作流程，并与参考化合物进行对照分析，参考化合物包括三异丙基硅基（TIPS）乙炔基取代型、醚包覆型以及我们此前报道的Geländer型并五苯。