2-Hydroxychalcone-β-Cyclodextrin Conjugate with pH-Modulated Photoresponsive Binding Properties

J Org Chem. 2022 Nov 4;87(21):14422-14432. doi: 10.1021/acs.joc.2c01875. Epub 2022 Oct 15.

Abstract

Stimuli-responsive supramolecular receptors are important building blocks for the construction of self-assembled functional materials. We report the design and synthesis of a pH- and light-responsive 2-hydroxychalcone-β-cyclodextrin conjugate (1-Ct) and its characterization by spectroscopic and computational methods. 1-Ct follows the typical reaction network of trans-chalcone-flavylium photoswitches. Upon light irradiation, 1-Ct can be photochemically converted into the cis-chalcone/hemiketal forms (1-Cc/1-B) under neutral pH conditions or to the flavylium cation (1-AH+) at acidic pH values. This stimuli-responsive β-cyclodextrin host, 1-Ct, was found to form stronger intramolecular self-inclusion complexes (Kintra = 14) than 1-AH+ (Kintra = 3) and weaker than 1-Cc/1-B (overall Kintra = 179), allowing control over their stability and binding properties by combinations of pH and light stimuli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chalcone* / chemistry
  • Chalcones* / chemistry
  • Hydrogen-Ion Concentration
  • beta-Cyclodextrins* / chemistry

Substances

  • 2'-hydroxychalcone
  • Chalcones
  • beta-Cyclodextrins
  • Chalcone