Abstract
Photoinduced processes in thiouracil derivatives have lately attracted considerable attention due to their suitability for innovative biological and pharmacological applications. Here, sub-20 fs broadband transient absorption spectroscopy in the near-UV are combined with CASPT2/MM decay path calculations to unravel the excited-state decay channels of water solvated 2-thio and 2,4-dithiouracil. These molecules feature linear absorption spectra with overlapping ππ* bands, leading to parallel decay routes which we systematically track for the first time. The results reveal that different processes lead to the triplet states population, both directly from the ππ* absorbing state and via the intermediate nπ* dark state. Moreover, the 2,4-dithiouracil decay pathways is shown to be strongly correlated either to those of 2- or 4-thiouracil, depending on the sulfur atom on which the electronic transition localizes.
| Original language | English |
|---|---|
| Pages (from-to) | 336-343 |
| Number of pages | 8 |
| Journal | Chemistry - A European Journal |
| Volume | 26 |
| Issue number | 1 |
| Early online date | 21 Nov 2019 |
| DOIs | |
| Publication status | Published - 2 Jan 2020 |
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Keywords
- CASPT2
- conical intersections
- QM/MM
- thiobases
- transient absorption
- ultrafast spectroscopy
Cite this
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A Unified Experimental/Theoretical Description of the Ultrafast Photophysics of Single and Double Thionated Uracils. / Teles-Ferreira, Danielle Cristina; Conti, Irene; Borrego-Varillas, Rocío; Nenov, Artur; Van Stokkum, Ivo H.M.; Ganzer, Lucia; Manzoni, Cristian; de Paula, Ana Maria; Cerullo, Giulio; Garavelli, Marco.
In: Chemistry - A European Journal, Vol. 26, No. 1, 02.01.2020, p. 336-343.Research output: Contribution to Journal › Article › Academic › peer-review
TY - JOUR
T1 - A Unified Experimental/Theoretical Description of the Ultrafast Photophysics of Single and Double Thionated Uracils
AU - Teles-Ferreira, Danielle Cristina
AU - Conti, Irene
AU - Borrego-Varillas, Rocío
AU - Nenov, Artur
AU - Van Stokkum, Ivo H.M.
AU - Ganzer, Lucia
AU - Manzoni, Cristian
AU - de Paula, Ana Maria
AU - Cerullo, Giulio
AU - Garavelli, Marco
PY - 2020/1/2
Y1 - 2020/1/2
N2 - Photoinduced processes in thiouracil derivatives have lately attracted considerable attention due to their suitability for innovative biological and pharmacological applications. Here, sub-20 fs broadband transient absorption spectroscopy in the near-UV are combined with CASPT2/MM decay path calculations to unravel the excited-state decay channels of water solvated 2-thio and 2,4-dithiouracil. These molecules feature linear absorption spectra with overlapping ππ* bands, leading to parallel decay routes which we systematically track for the first time. The results reveal that different processes lead to the triplet states population, both directly from the ππ* absorbing state and via the intermediate nπ* dark state. Moreover, the 2,4-dithiouracil decay pathways is shown to be strongly correlated either to those of 2- or 4-thiouracil, depending on the sulfur atom on which the electronic transition localizes.
AB - Photoinduced processes in thiouracil derivatives have lately attracted considerable attention due to their suitability for innovative biological and pharmacological applications. Here, sub-20 fs broadband transient absorption spectroscopy in the near-UV are combined with CASPT2/MM decay path calculations to unravel the excited-state decay channels of water solvated 2-thio and 2,4-dithiouracil. These molecules feature linear absorption spectra with overlapping ππ* bands, leading to parallel decay routes which we systematically track for the first time. The results reveal that different processes lead to the triplet states population, both directly from the ππ* absorbing state and via the intermediate nπ* dark state. Moreover, the 2,4-dithiouracil decay pathways is shown to be strongly correlated either to those of 2- or 4-thiouracil, depending on the sulfur atom on which the electronic transition localizes.
KW - CASPT2
KW - conical intersections
KW - QM/MM
KW - thiobases
KW - transient absorption
KW - ultrafast spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85076512713&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85076512713&partnerID=8YFLogxK
U2 - 10.1002/chem.201904541
DO - 10.1002/chem.201904541
M3 - Article
VL - 26
SP - 336
EP - 343
JO - Chemistry: A European Journal
JF - Chemistry: A European Journal
SN - 0947-6539
IS - 1
ER -