Premium
Polysubstituted 5‐Phenylazopyrimidines: Extremely Fast Non‐ionic Photochromic Oscillators
Author(s) -
Čechová Lucie,
Filo Juraj,
Dračínský Martin,
Slavov Chavdar,
Sun Dazhong,
Janeba Zlatko,
Slanina Tomáš,
Wachtveitl Josef,
Procházková Eliška,
Cigáň Marek
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202007065
Subject(s) - photochromism , isomerization , nanosecond , chemistry , ionic bonding , intramolecular force , relaxation (psychology) , ultrafast laser spectroscopy , absorption (acoustics) , photochemistry , thermal , microsecond , chemical physics , materials science , computational chemistry , spectroscopy , ion , stereochemistry , thermodynamics , laser , physics , optics , organic chemistry , social psychology , psychology , quantum mechanics , composite material , catalysis
Photochromic systems with an ultrahigh rate of thermal relaxation are highly desirable for the development of new efficient photochromic oscillators. Based on DFT calculations, we designed a series of 5‐phenylazopyrimidines with strong push–pull character in silico and observed very low energy barriers for the thermal ( Z )‐to‐( E ) isomerization. The structure of the ( Z )‐isomer of the slowest isomerizing derivative in the series was confirmed by NMR analysis with in situ irradiation at low temperature. The substituents can tune the lifetime of thermal back isomerization from hundreds of microseconds to several nanoseconds (8 orders of magnitude). The photoswitching parameters were extracted from transient absorption techniques and a dominant rotation mechanism of the ( Z )‐to‐( E ) thermal fading was proposed based on DFT calculations.