Wortmann, Svenja and Kutta, Roger Jan and Nuernberger, Patrick (2022) Monitoring the photochemistry of a formazan over 15 orders of magnitude in time. FRONTIERS IN CHEMISTRY, 10: 983342. ISSN 2296-2646,
Full text not available from this repository. (Request a copy)Abstract
2,3,5-triphenyltetrazolium chloride (TTC) may convert into phenyl-benzo[c]tetrazolocinnolium chloride (PTC) and 1,3,5-triphenylformazan (TPF) under irradiation with light. The latter reaction, albeit enzymatically rather than photochemically, is used in so-called TTC assays indicating cellular respiration and cell growth. In this paper, we address the photochemistry of TPF with time-resolved spectroscopy on various time scales. TPF is stabilized by an intramolecular hydrogen bond and switches photochemically via an E-Z isomerization around an N=N double bond into another TPF-stereoisomer, from which further isomerizations around the C=N double bond of the phenylhydrazone group are possible. We investigate the underlying processes by time-resolved spectroscopy in dependence on excitation wavelength and solvent environment, resolving several intermediates over a temporal range spanning 15 orders of magnitude (hundreds of femtoseconds to hundreds of seconds) along the reaction path. In a quantum-chemical analysis, we identify 16 stable ground-state isomers and discuss which ones are identified in the experimental data. We derive a detailed scheme how these species are thermally and photochemically interconnected and conclude that proton transfer processes are involved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | TRANS-AZOBENZENE; RESONANCE RAMAN; CIS-AZOBENZENE; COLORIMETRIC ASSAY; ULTRAFAST DYNAMICS; ABSORPTION-SPECTRA; PHOTOISOMERIZATION; MECHANISM; CONFIGURATIONS; ISOMERIZATION; formazan; photoisomerization; transient absorption; femtochemistry; streak camera; excited-state dynamics; proton transfer; ground-state dynamics |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Physical Chemistry I > Prof. Dr. Patrick Nürnberger |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 Feb 2024 07:58 |
| Last Modified: | 13 Feb 2024 07:58 |
| URI: | https://pred.uni-regensburg.de/id/eprint/56603 |
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