Photomodulation of ultrastable host–guest complexes in water and their application in light-controlled steroid release. Issue 16 (26th May 2022)

• Record Type: Journal Article
• Authors: Máximo, Patrícia; Colaço, Miriam; Pauleta, Sofia R.; Costa, Paulo J.; Pischel, Uwe; Parola, A. Jorge; Basílio, Nuno
• Is Part Of: Organic chemistry frontiers. Volume 9:Issue 16(2022)
• Page Start: 4238
• Page End: 4249
• Publication Date: 2022-05-26
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/d2qo00423b
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : Host–guest complexation of dithienylethene photoswitches with cucurbit[8]uril leads to photoresponsive binding pairs with picomolar affinity in water. Abstract : The cucurbit[8]uril (CB8) synthetic receptor is shown to form high-affinity host–guest complexes with dicationic dithienylethene (DTE) photoswitches in water. ITC experiments combined with computational studies suggest that the formation of the inclusion complexes is mainly driven by a combination of hydrophobic effects, ion–dipole, hydrogen- and chalcogen-bonding interactions. The binding affinities were observed to be much higher for the DTE closed isomers, reaching values in the picomolar range (up to 10 11 M −1 ) while the open isomers display up to 10 000-fold lower affinities, setting ideal conditions for the development of robust photoswitchable host–guest complexes. The light-responsive affinity of these photoswitches toward CB8 was explored to control the encapsulation and release of nanomolar affinity steroids via competitive guest replacement.