Ludwig-Maximilians-Universität München , Department für Chemie and Munich Center for Integrated Protein Science CIPSM, D-81377 Munich, Germany.
J Am Chem Soc. 2017 Oct 25;139(42):15060-15067. doi: 10.1021/jacs.7b07531. Epub 2017 Oct 13.
Hemiindigo is a long known chromophore that absorbs in the blue part of the spectrum but has almost completely been ignored as potential photoswitch. Herein we show how the absorption of hemiindigo is shifted to the red part of the visible spectrum and how nearly perfect photoswitching can be achieved using blue or green and red light. Five derivatives were investigated giving very high isomeric yields in both switching directions, i.e. >90% E isomer after irradiation with 470 to 530 nm light and 99% Z isomer with 590 up to 680 nm light. At the same time the thermal bistability is extraordinarily high leading to half-lives of the pure isomeric states of up to 83 years at 25 °C. The herein developed photoswitches show photochromism in the visible enabling the two isomeric states to be distinguished by the naked eye. Substituted hemiindigos therefore constitute extremely promising new photoswitches with excellent properties for applications in biology, chemistry, or material sciences.
半靛蓝是一种长期以来被人们熟知的发色团，它在光谱的蓝色部分吸收，但几乎完全被忽视作为潜在的光致变色开关。在这里，我们展示了如何将半靛蓝的吸收转移到可见光谱的红色部分，以及如何使用蓝光或绿光和红光实现近乎完美的光致开关。研究了五个衍生物，在两个开关方向上都获得了非常高的异构化产率，即在 470 到 530nm 光照射下，E 异构体的产率>90%，在 590 到 680nm 光照射下，Z 异构体的产率为 99%。同时，热不稳定性非常高，导致在 25°C 时纯异构态的半衰期长达 83 年。本文开发的光开关在可见光中表现出光致变色，使得两种异构体状态可以用肉眼区分。因此，取代的半靛蓝构成了具有出色性能的极有前途的新型光致变色开关，可应用于生物学、化学或材料科学。
