Chemical Z‐E isomer switching of arylazopyrazoles using acid
File(s)
Accepted version
Author(s)
Gibson, Rosina
Calbo, Joaquín
Fuchter, Matthew John
Type
Journal Article
Abstract
Arylazopyrazoles show significant potential as next‐generation photoswitches, in particular because of the high thermal stability of their Z‐isomers. Herein we investigate the potential to perform Z−E isomer chemical switching of arylazopyrazoles using acid. We show that acid‐accelerated isomerisation allows for robust Z−E switching using mild acids and opens up the possibility to use light‐acid cycles to near quantitatively and reversibly switch the arylazopyrazoles at room temperature. We attribute the chemical switching to azonium formation, facilitated by mesomeric stabilisation by the pyrazole ring. Coupled with their exceptionally long Z‐isomer half‐lives, we believe our study may open up a wider array of functional opportunities for the arylazopyrazoles.
Date Issued
2019-06-01
Date Acceptance
2019-04-09
Citation
ChemPhotoChem, 2019, 3 (6), pp.372-377
ISSN
2367-0932
Publisher
Wiley
Start Page
372
End Page
377
Journal / Book Title
ChemPhotoChem
Volume
3
Issue
6
Copyright Statement
© 2019 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim. This is the accepted version of the following article: Gibson, R. S., Calbo, J. and Fuchter, M. J. (2019), Chemical Z−E Isomer Switching of Arylazopyrazoles Using Acid. ChemPhotoChem. doi:10.1002/cptc.201900065, which has been published in final form at https://dx.doi.org/10.1002/cptc.201900065
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/R00188X/1
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Chemistry
azo compounds
isomerisation
NMR spectroscopy
photoswitches
protonation
CIS-TRANS ISOMERIZATION
MOLECULAR SWITCHES
THERMAL CIS
PHOTOSWITCHES
AZOBENZENE
CATALYSIS
LIGHT
FLUOROAZOBENZENES
MECHANISM
RED
Publication Status
Published
Date Publish Online
2019-04-09