Photophysics of Acyl- and Ester-DBD Dyes
- A new generation of wavelength-tunable, fluorescent dyes, so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes, were developed a few years ago, and they showed great potential as probes, for example, for fluorescence microscopy. However, their photophysics is not fully explored and leaves open questions regarding their large fluorescence Stokes shifts and sensitivity to solvent conditions of differently substituted DBD dyes. To improve the understanding of the influence of the substitution pattern of the DBD dyes on their respective photophysics, transient absorption spectroscopy (TAS) was used, that is, a pump-probe experiment on the femtosecond timescale. TAS allows measurements of excited states, ground state recovery, solvent relaxation, and fluorescence properties on time scales of up to several nanoseconds. Two different DBD dye samples were investigated: aryl- and ester-substituted DBD dyes. Experiments were carried out in solvents with different polarities using different excitation energies and at different viscosities.A new generation of wavelength-tunable, fluorescent dyes, so-called DBD ([1,3]dioxolo[4,5-f][1,3]benzodioxole) dyes, were developed a few years ago, and they showed great potential as probes, for example, for fluorescence microscopy. However, their photophysics is not fully explored and leaves open questions regarding their large fluorescence Stokes shifts and sensitivity to solvent conditions of differently substituted DBD dyes. To improve the understanding of the influence of the substitution pattern of the DBD dyes on their respective photophysics, transient absorption spectroscopy (TAS) was used, that is, a pump-probe experiment on the femtosecond timescale. TAS allows measurements of excited states, ground state recovery, solvent relaxation, and fluorescence properties on time scales of up to several nanoseconds. Two different DBD dye samples were investigated: aryl- and ester-substituted DBD dyes. Experiments were carried out in solvents with different polarities using different excitation energies and at different viscosities. Based on the experimental data and theoretical calculations, we were able to determine the conformational changes of the molecule due to electronic excitation and were able to investigate solvent relaxation processes for both types of DBD dyes. By generalizing the theory for quadrupole-induced solvent relaxation developed by Togashi et al., we derived quadrupole moments of both molecules in the ground and excited state. Our data showed differences in the binding of polar solvent molecules to the dyes depending on the substituent on the DBD dye. In the case of water as the solvent, an additional efficient quenching process in the electronically excited state was revealed, which was indicated by the observation of solvated electrons in the TAS signals.…
Author details: | Toni HaubitzORCiD, Leonard JohnORCiDGND, Pablo WessigORCiDGND, Michael Uwe KumkeORCiDGND |
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DOI: | https://doi.org/10.1021/acs.jpca.9b02973 |
ISSN: | 1089-5639 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/31067057 |
Title of parent work (English): | the journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory |
Subtitle (English): | Quadrupole-Induced Solvent Relaxation Investigated by Transient Absorption Spectroscopy |
Publisher: | American Chemical Society |
Place of publishing: | Washington |
Publication type: | Article |
Language: | English |
Date of first publication: | 2019/05/08 |
Publication year: | 2019 |
Release date: | 2021/01/25 |
Volume: | 123 |
Issue: | 22 |
Number of pages: | 10 |
First page: | 4717 |
Last Page: | 4726 |
Funding institution: | Federal Ministry for Economic Affairs and Energy [02E11415F] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Peer review: | Referiert |