Polysubstituted 5‐Phenylazopyrimidines Extremely Fast Non‐Ionic Photochromic Oscillators

0524472 - ÚOCHB 2021 RIV DE eng J - Journal Article
Čechová, Lucie - Filo, J. - Dračínský, Martin - Slavov, C. - Sun, D. - Janeba, Zlatko - Slanina, Tomáš - Wachtveitl, J. - Procházková, Eliška - Cigáň, M.
Polysubstituted 5‐Phenylazopyrimidines Extremely Fast Non‐Ionic Photochromic Oscillators.
Angewandte Chemie - International Edition. Roč. 59, č. 36 (2020), s. 15590-15594. ISSN 1433-7851. E-ISSN 1521-3773
R&D Projects: GA ČR(CZ) GA18-11851S
Institutional support: RVO:61388963
Keywords : azopyrimidines * DFT calculations * in situ irradiation NMR spectroscopy * photochromic oscillators * ultrafast spectroscopy
OECD category: Physical chemistry
Impact factor: 15.336, year: 2020
Method of publishing: Limited access
https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202007065

Photochromic systems with ultrahigh rate of thermal relaxation are highly desirable for 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 of thermal ( Z )‐to‐( E ) isomerization. The structure of the ( Z )‐isomer of the slowest derivative in the series was confirmed by NMR with in situ irradiation at low temperature. The substituents can tune the lifetime of thermal back isomerization from hundreds of ms to several ns (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.
Permanent Link: http://hdl.handle.net/11104/0308828