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pH Tuning of Water‐Soluble Arylazopyrazole Photoswitches
pH Tuning of Water‐Soluble Arylazopyrazole Photoswitches
- Source :
- Chemistry (Weinheim an Der Bergstrasse, Germany)
- Publication Year :
- 2020
- Publisher :
- Wiley, 2020.
-
Abstract
- Arylazopyrazoles are an emerging class of photoswitches with redshifted switching wavelength, high photostationary states, long thermal half‐lives and facile synthetic access. Understanding pathways for a simple modulation of the thermal half‐lives, while keeping other parameters of interest constant, is an important aspect for out‐of‐equilibrium systems design and applications. Here, it is demonstrated that the thermal half‐life of a water‐soluble PEG‐tethered arylazo‐bis(o‐methylated)pyrazole (AAP) can be tuned by more than five orders of magnitude using simple pH adjustment, which is beyond the tunability of azobenzenes. The mechanism of thermal relaxation is investigated by thorough spectroscopic analyses and density functional theory (DFT) calculations. Finally, the concepts of a tunable half‐life are transferred from the molecular scale to the material scale. Based on the photochromic characteristics of E‐ and Z‐AAP, transient information storage is showcased in form of light‐written patterns inside films cast from different pH, which in turn leads to different times of storage. With respect to prospective precisely tunable materials and time‐programmed out‐of‐equilibrium systems, an externally tunable half‐life is likely advantageous over changing the entire system by the replacement of the photoswitch.<br />Arylazopyrazoles are an emerging class of photoswitches with redshifted switching wavelength, high photostationary states, long thermal half‐lives and facile synthetic access. Understanding pathways for a simple modulation of the thermal half‐lives, while keeping other parameters of interest constant, is an important aspect for out‐of‐equilibrium systems design and applications. Here, it is demonstrated that the thermal half‐life of a water‐soluble PEG‐tethered arylazo‐bis(o‐methylated)pyrazole (AAP) can be tuned by more than five orders of magnitude using simple pH adjustment, which is beyond the tunability of azobenzenes.
- Subjects :
- 010402 general chemistry
01 natural sciences
Catalysis
Photochromism
Photoswitches | Hot Paper
Thermal
thermal half-life
Full Paper
arylazopyrazoles
Photoswitch
light-responsive system
010405 organic chemistry
business.industry
Chemistry
light-adaptive materials
Organic Chemistry
General Chemistry
Full Papers
photoswitches
0104 chemical sciences
Wavelength
Orders of magnitude (time)
Modulation
Optoelectronics
Density functional theory
Transient (oscillation)
business
Subjects
Details
- ISSN :
- 15213765 and 09476539
- Volume :
- 26
- Database :
- OpenAIRE
- Journal :
- Chemistry – A European Journal
- Accession number :
- edsair.doi.dedup.....f81869660544d4f239fed07f1b149759
- Full Text :
- https://doi.org/10.1002/chem.202000659