Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund (Germany).
Angew Chem Int Ed Engl. 2014 Jan 7;53(2):591-4. doi: 10.1002/anie.201307016. Epub 2013 Nov 26.
The photochemical properties of indigo, a widely used industrial dye, has attracted both experimentalists and theoreticians from the beginning. Especially the high photostability of indigo has been the subject of intensive research. Recently, it was proposed that after photoexcitation an intramolecular proton transfer followed by a nonradiative relaxation to the ground state promote photostability. In indigo the hydrogen bond and the proton transfer occur between the opposing hemiindigo parts. Here, we provide experimental and theoretical evidence that a hydrogen transfer within one hemiindigo or hemithioindigo part is sufficient to attain photostability. This concept can serve as an interesting strategy towards new photostable dyes for the visible part of the spectrum.
靛蓝是一种广泛应用的工业染料，其光化学性质从一开始就引起了实验家和理论家的关注。特别是靛蓝的高光稳定性一直是深入研究的课题。最近，有人提出，光激发后，分子内质子转移，然后非辐射弛豫到基态，这促进了光稳定性。在靛蓝中，氢键和质子转移发生在相对的半靛蓝部分之间。在这里，我们提供了实验和理论证据，证明一个半靛蓝或半硫靛蓝部分内的氢转移足以达到光稳定性。这个概念可以作为一种有趣的策略，为可见光谱部分设计新的光稳定染料。
