Abstract
Substituted indigo derivatives undergo photoisomerization of the central double bond if both nitrogen atoms are functionalized. Indigo itself however does not photoisomerize because of a competing and highly efficient excited-state proton transfer. In this work, we show that also mono-arylated indigo undergoes photoisomerization despite still possessing one nitrogen-bound proton and the likely presence of a competing intramolecular excited-state proton transfer. The two different isomers exhibit strongly different absorptions and therefore can be distinguished by the naked eye. Different to diaryl-substituted indigo, thermal decay of the metastable cisisomers of mono-arylated derivatives can be greatly accelerated by small amounts of water (by more than a factor of 300 for measured half-lives). Such tunability is of high interest for applications that require quick and autonomous switching-off of photoresponsive trigger units.
Item Type: | Journal article |
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Research Centers: | Center for Integrated Protein Science Munich (CIPSM) |
Subjects: | 500 Science > 540 Chemistry |
ISSN: | 2367-0932 |
Language: | English |
Item ID: | 68212 |
Date Deposited: | 19. Jul 2019, 12:24 |
Last Modified: | 04. Nov 2020, 13:50 |