Theoretical Investigation of the Effect of Alkylation and Bromination on Intersystem Crossing in BODIPY-Based Photosensitizers

0547507 - ÚFCH JH 2022 RIV US eng J - Journal Article
Baig, Mirza Wasif - Pederzoli, Marek - Kývala, M. - Cwiklik, Lukasz - Pittner, Jiří
Theoretical Investigation of the Effect of Alkylation and Bromination on Intersystem Crossing in BODIPY-Based Photosensitizers.
Journal of Physical Chemistry B. Roč. 125, č. 42 (2021), s. 11617-11627. ISSN 1520-6106. E-ISSN 1520-5207
R&D Projects: GA ČR(CZ) GA18-26751S; GA ČR(CZ) GA19-06860S
Institutional support: RVO:61388955
Keywords : BOPIDY-Based Photosenzitizers * photodynamic therapy * alkylation
OECD category: Physical chemistry
Impact factor: 3.466, year: 2021
Method of publishing: Limited access

Halogenated and alkylated BODIPY derivatives are reported as suitable candidates for their use as photosensitizers in photodynamic therapy due to their efficient intersystem crossing (ISC) between states of different spin multiplicities. Spin–orbit couplings (SOCs) are evaluated using an effective one-electron spin–orbit Hamiltonian for brominated and alkylated BODIPY derivatives to investigate the quantitative effect of alkyl and bromine substituents on ISC. BODIPY derivatives containing bromine atoms have been found to have significantly stronger SOCs than alkylated BODIPY derivatives outside the Frank–Condon region while they are nearly the same at local minima. Based on calculated time-dependent density functional theory (TD-DFT) vertical excitation energies and SOCs, excited-state dynamics of three BODIPY derivatives were further explored with TD-DFT surface hopping molecular dynamics employing a simple accelerated approach. Derivatives containing bromine atoms have been found to have very similar lifetimes, which are much shorter than those of the derivatives possessing just the alkyl moieties. However, both bromine atoms and alkyl moieties reduce the HOMO/LUMO gap, thus assisting the derivatives to behave as efficient photosensitizers.
Permanent Link: http://hdl.handle.net/11104/0323719