Synthesis, Structure, and Photochemical Behavior of [5]Heli-viologen Isomers

The syntheses of isomeric helical viologens that have potential applications in supramolecular chemistry and catalysis have been developed. The structures of the molecules and their solid-state packing motifs have been determined by X-ray crystallography. Computational studies demonstrate that the magnitude of their racemization barriers is primarily determined by the identity of the helical scaffold and is insensitive to the placement of the viologen functional group. The isomers are similar in their photophysical behavior but very different in their photochemical behavior.本研究开发了具备超分子化学与催化应用潜力的异构螺旋紫精的合成方法。通过X射线晶体学（X-ray crystallography）确定了该类分子的结构及其固态堆积模体。计算化学研究表明，此类化合物的消旋能垒大小主要由螺旋骨架的结构决定，且不受紫精官能团取代位置的影响。该系列异构体的光物理行为较为相似，但光化学行为差异显著。