Photophysical Heavy-Atom Effect in Iodinated Metallocorroles: Spin-Orbit Coupling and Density of States
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F18%3A00494128" target="_blank" >RIV/61388955:_____/18:00494128 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1021/acs.jpca.8b05311" target="_blank" >http://dx.doi.org/10.1021/acs.jpca.8b05311</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpca.8b05311" target="_blank" >10.1021/acs.jpca.8b05311</a>
Alternative languages
Result language
angličtina
Original language name
Photophysical Heavy-Atom Effect in Iodinated Metallocorroles: Spin-Orbit Coupling and Density of States
Original language description
Excited-state dynamics and electronic structures of Al and Ga corrole complexes were studied as a function of the number of β-pyrrole iodine substituents. Using spectrally broad-band femtosecond-resolved fluorescence upconversion, we determined the kinetics of the Soret fluorescence decay, the concomitant rise and subsequent decay of the Q-band fluorescence, as well as of the accompanying vibrational relaxation. Iodination was found to accelerate all involved processes. The time constant of the internal conversion from the Soret to the Q states decreases from 320-540 to 70-185 fs upon iodination. Vibrational relaxation then occurs with about 15 and 0.36-1.4 ps lifetime for iodine-free and iodinated complexes, respectively. Intersystem crossing to the lowest triplet is accelerated up to 200 times from nanoseconds to 15-24 ps. Its rate correlates with the iodine p(Ï€) participation in the corrole Ï€-system and the spin-orbit coupling (SOC) strength. TDDFT calculations with explicit SOC show that iodination introduces a manifold of low-lying singlet and triplet iodine ↠corrole charge-transfer (CT) states. These states affect the photophysics by (i) providing a relaxation cascade for the Soret ↠Q internal conversion and cooling and (ii) opening new SOC pathways whereby CT triplet character is admixed into both Q singlet excited states. In addition, SOC between the higher Q singlet and the Soret triplet is enhanced as the iodine participation in frontier corrole Ï€-orbitals increases. Our observations that iodination of the chromophore periphery affects the whole photocycle by changing the electronic structure, spin-orbit coupling, and the density of states rationalize the ´´heavy-atom effect´´ and have implications for controlling excited-state dynamics in a range of triplet photosensitizers.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
<a href="/en/project/GA17-01137S" target="_blank" >GA17-01137S: Electron Transfer in (Bio)Molecular Systems: Time-Resolved Vibrational Spectroscopy and Theory</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Physical Chemistry A
ISSN
1089-5639
e-ISSN
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Volume of the periodical
122
Issue of the periodical within the volume
37
Country of publishing house
US - UNITED STATES
Number of pages
11
Pages from-to
7256-7266
UT code for WoS article
000445711900002
EID of the result in the Scopus database
2-s2.0-85053197585