Mrozek, Thomas and Goerner, Helmut and Daub, Joerg (2001) Multimode-photochromism based on strongly coupled dihydroazulene and diarylethene. CHEMISTRY-A EUROPEAN JOURNAL, 7 (5). pp. 1028-1040. ISSN 0947-6539
Full text not available from this repository.Abstract
Synthesis and photophysical/photochemical investigations of 1,8a-dihydro-2,3-bis(2,5-dimethy-3-thienyl)-azulene-1,1-dicarbonitrile (1A) and 1,8a-dihydro-2,3-diphenylazulene-1,1-dicarbonitrile (2A) are reported. The photoprocesses and thermal reactions of systems 1 and 2 were studied by time-resolved and steady-state techniques under various conditions. The dihydroazulene (DHA)-dithienylethene (DTE) conjugate 1A is photochemically converted into the dihydrothienobenzothiophene (DHB) isomer 1C and the vinyl-heptafulvene (VHF) isomer 1B. System 2 exhibits exclusively DHA/VHF photochromism. For both systems the VHF form thermally reverts back into the DHA form. Their rate constant (k(B -->A)) increases with the solvent polarity and the relaxation kinetics proceed by means of an activation barrier of 65-80 kJ mol(-1); k(B -->A) and the activation parameters of the isomerisation reactions are rather similar. The photostationary state of the 1A --> 1B and 1A --> 1C photoisomerisation is sensitive to the irradiation wavelength. The concept of cycloswitching is discussed.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | VINYLHEPTAFULVENE PHOTOCHROMISM; DIHYDROAZULENE/VINYLHEPTAFULVENE PHOTOCHROMISM; ARYL GROUPS; SUBSTITUENTS; RING; BACTERIORHODOPSIN; DERIVATIVES; BEHAVIOR; SOLVENT; FILMS; cycloswitching; diarylethenes; dihydroazulenes; electron transfer; photochromism |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie > Alumni or Retired Professors > Prof. Dr. Jörg Daub |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 08 Feb 2022 17:02 |
| Last Modified: | 08 Feb 2022 17:02 |
| URI: | https://pred.uni-regensburg.de/id/eprint/41672 |
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