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Chemistry of 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium. A photochromic system switching from yellow to green

Paper ID Volume ID Publish Year Pages File Format Full-Text
27024 43995 2013 7 PDF Available
Title
Chemistry of 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium. A photochromic system switching from yellow to green
Abstract

•The so-called styrylflavylium compounds are promising alternatives to anthocyanins and related compounds.•They follow the same network of reactions of anthocyanins including hydration, tautomerization and cis–trans isomerization.•The absorption spectra of styrylflavyliums are red shifted in comparison with the flavylium analogues.•A switching photochromic system from yellow to green is obtained in the presence of CTAB micelles.

The bio-inspired compound 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium (styrylflavylium) was synthesized through the insertion of a double bond between rings B and C of the flavylium cation. The pH dependent network of chemical reactions of the new compound is similar to the one of anthocyanins and related compounds. The styrylflavylium is the dominant species at very low pH values. At moderately acidic pH values the respective quinoidal base is formed by deprotonation of the styrylflavylium in competition with the hydration reaction to give an analogous of the anthocyanins hemiketal. The cis-chalcone is formed through the hemiketal (ring C opening) and the trans-chalcone by the cis–trans isomerization of the former. All the rate and equilibrium constants of these reactions have been calculated, permitting to completely characterize the styrylflavylium network. While in water no photochromism could be observed in the presence of CTAB micelles, formation of the flavylium cation upon irradiation of the trans-chalcone takes place. Complexation of the quinoidal base with Al3+ was clearly identified.

Graphical abstractThe network of chemical reactions of the bio-inspired compound 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium is identical to anthocyanins. A photochromic system switching from yellow to green is obtained. The presence of a cathecol susbtituent can extend the network to metal inputs.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Anthocyanins; Styrylflavylium; Photochromism; Stopped flow; CTAB; Micelles
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Chemistry of 7,8-dihydroxy-2-(4-dimethylaminostyryl)-1-benzopyrylium. A photochromic system switching from yellow to green
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 263, 1 July 2013, Pages 17–23
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us