Photosalient and thermosalient crystalline hemithioindigo-anthracene based isomeric photoswitches. Issue 21 (14th May 2021)

• Record Type: Journal Article
• Authors: Hean, Duane; Alde, Luis G.; Wolf, Michael O.
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 21(2021)
• Page Start: 6789
• Page End: 6795
• Publication Date: 2021-05-14
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1tc01358k
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Single crystals of Z - and E -isomers of an anthracene-functionalized hemithioindigo show thermosalient and photosalient effects respectively. Abstract : Hemithioindigos are emerging photoswitches that have been found to undergo either [2+2] cycloaddition or reversible photoisomerization reactions. In this work we present a hemithioindigo photoswitch modified with an anthracene moiety, 2-[(anthracen-9-yl)methylidene]-2, 3-dihydro-1-benzothiophen-3-one (HTI-An ) and report the responses to thermal and light stimulation. In solution and in the crystalline state, HTI-An was found to selectively undergo a reversible Z – E photoisomerization reaction. Upon exposure of crystals of ( Z )-HTI-An to UV light a photochromic effect is observed, while heating at 130 °C prompted a phase transition coupled to a thermosalient response. Upon visible light exposure, ( E )-HTI-An crystals undergo a photosalient response, where heating to 180 °C induces thermal isomerization reversion while preserving the crystal structural integrity. Thus, HTI-An is an example of a photosalient and thermosalient responsive photoswitch adding to the library of stimuli responsive mechanical compounds.