Among the plethora of photochromes reported so far, azobenzene has been proven to be the most suitable photoswitch for molecular systems and materials, due to its highly efficient and clean E-Z photoisomerization. Here we report two ammonium-based molecular axles bearing one or two p-cyanoazobenzene units at the extremities, able to form pseudorotaxanes with a crown ether macrocycle. The photochemistry of these compounds was studied in the isolated forms and in the pseudorotaxanes, showing that the functionalization speeds up the threading process without affecting the photochemical properties of the system. These results suggest that the investigated pseudorotaxanes can form the basis of new prototypes of artificial molecular-level pumps.
在迄今报道的大量光致变色剂中,
偶氮苯因其高效、清洁的 E-Z 光异构化作用,已被证明是最适合用于分子系统和材料的光开关。在此,我们报告了两种
铵基分子轴,其末端含有一个或两个对
氰基
偶氮苯单元,能够与
冠醚大环形成伪光催化剂。对这些化合物在分离形式和假轴烷中的光
化学特性进行了研究,结果表明,官能化加速了穿线过程,而不会影响体系的光
化学特性。这些结果表明,所研究的假轴环可以成为人工分子级泵新原型的基础。