Photochromism of the natural dye 7,4 '-dihydroxy-5-methoxyflavylium (dracoflavylium) in the presence of (2-hydroxypropyl)-beta-cyclodextrin

Tania Lopes-Costa, Nuno Basilio, Jose M. Pedrosa, Fernando Pina

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

A photochromic system based on dracoflavylium, a natural pigment extracted from Dragon's blood, a resin appearing in the injury parts of the tree Dracaena draco, is studied in water. The photochromism arises from the irradiation of the trans-chalcone, giving a mixture of flavylium cation/ quinoidal base as a photoproduct via cis-chalcone and hemiketal. The performance of the photochromic system can be improved in the presence of (2-hydroxypropyl)-beta-cyclodextrin. A mathematical model to account for the details of the kinetics and thermodynamics of the system was deduced. The model is general for all the host-guest systems involving the flavylium network of chemical reactions with 1 : 1 stoichiometric association.

Original languageEnglish
Pages (from-to)1420-1426
Number of pages7
JournalPhotochemical and Photobiological Sciences
Volume13
Issue number10
DOIs
Publication statusPublished - Oct 2014

Keywords

  • BETA-CYCLODEXTRIN
  • FLAVYLIUM ION
  • HYDRATION

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