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Push-Pull Stiff-Stilbene: Proton-Gated Visible-Light Photoswitching and Acid-Catalyzed Isomerization.

ABSTRACT: Donor-acceptor substituted stiff-stilbene is shown to undergo isomerization induced by visible light avoiding the need for harmful UV light. This visible-light photoswitching is inhibited by protonation of the dimethylamino-donor unit, disrupting the push-pull character and thus, gating of the photochromic properties is allowed by acid/base addition. Remarkably, the addition of a mild acid also triggers fast thermal back-isomerization, which is unprecedented for stiff-stilbene photoswitches usually having a very high energy barrier for this process. These combined features offer unique orthogonal control over switching behavior by light and protonation, which is investigated in detail by ¹ H NMR and UV/Vis spectroscopy. In addition, TD-DFT calculations are used to gain further insight into the absorption properties. Our results will help elevating the level of control over dynamic behavior in stiff-stilbene applications.

SUBMITTER: Villaron D

PROVIDER: S-EPMC9298359 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

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Push-Pull Stiff-Stilbene: Proton-Gated Visible-Light Photoswitching and Acid-Catalyzed Isomerization.

Villarón David D Duindam Nol N Wezenberg Sander J SJ

Chemistry (Weinheim an der Bergstrasse, Germany) 20211021 69

Donor-acceptor substituted stiff-stilbene is shown to undergo isomerization induced by visible light avoiding the need for harmful UV light. This visible-light photoswitching is inhibited by protonation of the dimethylamino-donor unit, disrupting the push-pull character and thus, gating of the photochromic properties is allowed by acid/base addition. Remarkably, the addition of a mild acid also triggers fast thermal back-isomerization, which is unprecedented for stiff-stilbene photoswitches usua ...[more]

PMID: 34605565

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