Projects per year
Abstract
The ultrafast dynamics of a bimolecular excited state proton transfer (ESPT) reaction between the photoacid 7-hydroxy-4-(trifluoromethyl)-1-coumarin (CouOH) and 1-methylimidazole (MI) base in aprotic chloroform-d1 solution were investigated using ultrafast transient infrared (TRIR) and transient absorption (TA) spectroscopies. The excited state lifetime of the photoacid in solution is relatively short (52 ps) which at the millimolar photoacid and base concentrations used in our study precludes any diffusion-controlled bimolecular ESPT reactions. This allows the prompt ESPT reaction between hydrogen bonded CouOH and MI molecules to be studied in isolation, and the ‘contact’ ESPT dynamics to be unambiguously determined. Our time resolved studies reveal ultrafast ESPT from the CouOH moiety to hydrogen bonded MI molecules occurs within ~1 ps, tracked by unequivocal spectroscopic signatures of CouO–* photoproducts which are formed in tandem with HMI+. Some of the ESPT photoproducts subsequently π-stack to form exciplexes on a ~35 ps timescale, minimizing the attractive Coulombic forces between the oppositely charged aromatic molecules. For the concentrations of CouOH and MI used in our study (up to 8 mM), we saw no evidence for excited state tautomerization of coumarin anions.
Original language | English |
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Pages (from-to) | 4745-4756 |
Number of pages | 12 |
Journal | Journal of Physical Chemistry B |
Volume | 123 |
Issue number | 22 |
Early online date | 8 May 2019 |
DOIs | |
Publication status | Published - 6 Jun 2019 |
Fingerprint
Dive into the research topics of 'Following Bimolecular Excited-State Proton Transfer between Hydroxycoumarin and Imidazole Derivatives'. Together they form a unique fingerprint.Projects
- 2 Finished
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Elucidation of energy and charge transportation mechanisms in biomolecules and nanomaterials
Oliver, T. (Principal Investigator)
1/12/17 → 31/03/21
Project: Research
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Exploring Delocalised Energy Transport in Bacterial Reaction Centres
Oliver, T. (Principal Investigator)
1/02/17 → 31/07/18
Project: Research
Student theses
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Ultrafast photoinduced bimolecular proton, electron and energy transfer
Amoruso, G. (Author), Oliver, T. (Supervisor) & Orr-Ewing, A. (Supervisor), 2 Dec 2021Student thesis: Doctoral Thesis › Doctor of Philosophy (PhD)
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Datasets
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Following Bimolecular Excited State Proton Transfer Between Hydroxycoumarin and Imidazole Derivatives
Oliver, T. (Creator), Duchi, M. (Creator), Taylor, V. C. A. (Creator) & Amoruso, G. (Creator), University of Bristol, 17 May 2019
DOI: 10.5523/bris.2q1nt2ffjh96f28sf4uc3q57y2, https://data.bris.ac.uk/data/dataset/2q1nt2ffjh96f28sf4uc3q57y2
Dataset
Activities
- 1 Hosting an academic visitor
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Stephen E. Bradforth
Oliver, T. (Host)
3 Sept 2018 → 21 Sept 2018Activity: Hosting a visitor types › Hosting an academic visitor