Thioetherification Inducing Efficient Excited Triplet State and Singlet Oxygen Generation: Heavy Atom-Free BODIPY Photosensitizer Based on the S1(n,π*) State

Hu，Wenbin1; Zhang，Xian Fu2,3; Liu，Mingyu1

2021

10.1021/acs.jpcc.1c00001

Journal of Physical Chemistry C   影响因子和分区

1932-7447

1932-7455

We have examined the ability of the newly synthesized thioalkyl and thiophenyl (SR) BODIPYs to generate the excited triplet state (T1) using the laser flash photolysis technique. Compared to the unsubstituted BODIPY parent, SR BODIPYs are much more efficient in generating T1. We have also determined the capability of the SR BODIPYs to yield singlet oxygen O2(1Δg) using two methods: (1) measuring the steady state and time-resolved NIR phosphorescence that peaked at 1270 nm; (2) recording DPBF decomposition caused by the reaction with singlet oxygen. The results show that both thioalkyl and thiophenyl very remarkably increase the quantum yield of singlet oxygen formation up to 0.83 from 0.10. To understand the mechanism, we have studied the related photophysics using steady state and time-resolved fluorescence and UV-vis absorption, as well as quantum chemical calculations based on Density Functional Theory. Both the thioalkyl and thiophenyl remarkably decrease the quantum yield of fluorescence and shorten the fluorescence lifetime of BODIPYs, they also cause the occurrence of a new S1(n,π*) with a slightly lower energy than S1(π,π*). Since intersystem crossing (ISC) from S1(n,π*) to T1(π,π*) is symmetrically allowed, while ISC from S1(π,π*) to T1(π,π*) is symmetrically forbidden, this explains why SR presence renders BODIPY efficient photosensitizer for excited triplet state and singlet oxygen generation. SR induced efficient T1 formation is different from the cases of carbonyl (C═O) or thiocarbonyl (C═S). This finding provides a new method to get efficient heavy atom free photosensitizers, which is important in developing new generation photosensitizers for photodynamic therapy, photochemical up conversion of near IR sunlight in solar cell, and photoredox catalysis.

SCI ; EI

英语

其他

National Natural Science Foundation of China[62074073] ; Natural Science Foundation of Shenzhen City[JCYJ20190809154005668]

Chemistry ; Science & Technology - Other Topics ; Materials Science

Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000629169900034

AMER CHEMICAL SOC

20211410167385

Density functional theory ; Excited states ; Fluorescence ; Gas generators ; Photodynamic therapy ; Photolysis ; Photophysics ; Quantum chemistry ; Quantum theory ; Quantum yield

Medicine and Pharmacology:461.6 ; Gas Fuels:522 ; Light/Optics:741.1 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Quantum Theory; Quantum Mechanics:931.4

2-s2.0-85103380568

Scopus

1.Department of Chemical Engineering,Hebei Normal University of Science and Technology,Qinhuangdao, Hebei Province,066004,China
2.Department of Material Science and Engineering,Southern University of Sciences and Technology,Shenzhen City, Guangdong Province,518055,China
3.MPC Technologies,Hamilton,L8S 3H4,Canada

Hu，Wenbin,Zhang，Xian Fu,Liu，Mingyu. Thioetherification Inducing Efficient Excited Triplet State and Singlet Oxygen Generation: Heavy Atom-Free BODIPY Photosensitizer Based on the S1(n,π*) State[J]. Journal of Physical Chemistry C,2021,125(9):5233-5242.

Hu，Wenbin,Zhang，Xian Fu,&Liu，Mingyu.(2021).Thioetherification Inducing Efficient Excited Triplet State and Singlet Oxygen Generation: Heavy Atom-Free BODIPY Photosensitizer Based on the S1(n,π*) State.Journal of Physical Chemistry C,125(9),5233-5242.

Hu，Wenbin,et al."Thioetherification Inducing Efficient Excited Triplet State and Singlet Oxygen Generation: Heavy Atom-Free BODIPY Photosensitizer Based on the S1(n,π*) State".Journal of Physical Chemistry C 125.9(2021):5233-5242.