Predicting fluorescence quantum yields for molecules in solution: A critical assessment of the harmonic approximation and the choice of the lineshape function
Please always quote using this URN: urn:nbn:de:bvb:20-opus-199305
- For the rational design of new fluorophores, reliable predictions of fluorescence quantum yields from first principles would be of great help. However, efficient computational approaches for predicting transition rates usually assume that the vibrational structure is harmonic. While the harmonic approximation has been used successfully to predict vibrationally resolved spectra and radiative rates, its reliability for non-radiative rates is much more questionable. Since non-adiabatic transitions convert large amounts of electronic energy intoFor the rational design of new fluorophores, reliable predictions of fluorescence quantum yields from first principles would be of great help. However, efficient computational approaches for predicting transition rates usually assume that the vibrational structure is harmonic. While the harmonic approximation has been used successfully to predict vibrationally resolved spectra and radiative rates, its reliability for non-radiative rates is much more questionable. Since non-adiabatic transitions convert large amounts of electronic energy into vibrational energy, the highly excited final vibrational states deviate greatly from harmonic oscillator eigenfunctions. We employ a time-dependent formalism to compute radiative and non-radiative rates for transitions and study the dependence on model parameters. For several coumarin dyes we compare different adiabatic and vertical harmonic models (AS, ASF, AH, VG, VGF, VH), in order to dissect the importance of displacements, frequency changes and Duschinsky rotations. In addition we analyze the effect of different broadening functions (Gaussian, Lorentzian or Voigt). Moreover, to assess the qualitative influence of anharmonicity on the internal conversion rate, we develop a simplified anharmonic model. We adress the reliability of these models considering the potential errors introduced by the harmonic approximation and the phenomenological width of the broadening function.…
Author: | Alexander Humeniuk, Margarita Bužančić, Joscha Hoche, Javier Cerezo, Roland Mitric, Fabrizio Santoro, Vlasta Bonačić-Koutecky |
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URN: | urn:nbn:de:bvb:20-opus-199305 |
Document Type: | Preprint |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Physikalische und Theoretische Chemie |
Language: | English |
Parent Title (English): | The Journal of Chemical Physics |
Year of Completion: | 2020 |
Source: | Journal of Chemical Physics 152, 054107 (2020); https://doi.org/10.1063/1.5143212 |
URL: | https://doi.org/10.1063/1.5143212 |
Sonstige beteiligte Institutionen: | Center of Excellence for Science and Technology - Integration of Mediterranean region (STIM), Faculty of Science, University of Split, Poljička cesta 35, 2100 Split, Croatia |
Sonstige beteiligte Institutionen: | Departamento de Química, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain |
Sonstige beteiligte Institutionen: | Istituto di Chimica dei Composti Organometallici (ICCOM–CNR), Area della Ricerca del CNR, Via Moruzzi 1, I-56124 Pisa, Italy. |
Sonstige beteiligte Institutionen: | Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 541 Physikalische Chemie |
Tag: | fluorescence quantum yield |
Release Date: | 2020/02/10 |
EU-Project number / Contract (GA) number: | 646737 |
OpenAIRE: | OpenAIRE |
Note: | Accepted Manuscript. |
Note: | This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in A. Humeniuk et al. J. Chem. Phys. 152, 054107 (2020); https://doi.org/10.1063/1.5143212 and may be found at https://doi.org/10.1063/1.5143212. |
Licence (German): | Deutsches Urheberrecht |