Substituted Phosphorous Triazatetrabenzocorroles: Correlation Between Structure and Excited State Properties

Xian-Fu Zhang; Yakuan Chang; Yanling Peng; Fushi Zhang

doi:10.1071/CH09020

RESEARCH ARTICLE

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Substituted Phosphorous Triazatetrabenzocorroles: Correlation Between Structure and Excited State Properties

Xian-Fu Zhang ^A ^B ^C , Yakuan Chang ^A , Yanling Peng ^A and Fushi Zhang ^B

+ Author Affiliations

- Author Affiliations

^A Chemistry Department, Hebei Normal University of Science & Technology, Qinhuangdao, Hebei Province, 066004, China.

^B Chemistry Department, Tsinghua University, Beijing, 100084, China.

^C Corresponding author. Email: zhangxianfu@tsinghua.org.cn

Australian Journal of Chemistry 62(5) 434-440 https://doi.org/10.1071/CH09020
Submitted: 11 January 2009 Accepted: 12 March 2009 Published: 15 May 2009

Abstract

The photophysical properties of five novel phthalocyanine analogues, dihydroxy phosphorus(v) triazatetrabenzocorrole (PTBC) substituted with –NO₂, –SO₃H, OⁱPr, and –NH₂, respectively, were studied by a combination of absorption, steady-state emission, time-resolved fluorescence, and laser flash photolysis. All substituents, even for the strong electron-donating –NH₂, cause only a slight red shift of their absorption and emission maxima. These complexes are generally monomeric in organic solution, whereas the sulfonated derivative, PTBC(SO₃H)₄, slightly aggregates in aqueous buffer. Distinct from phthalocyanines, PTBCs substituted with –NO₂ or –NH₂ still show high photo activities. The electron-withdrawing –NO₂ and –SO₃H decrease the fluorescence quantum yield but increase the triplet formation yield to 0.76 and 0.82, respectively. All PTBCs have long triplet lifetimes and hence generate singlet oxygen efficiently with a quantum yield from 0.43 to 0.75. Together with the ground-state absorption properties, the results suggest that these PTBCs may be used as excellent photosensitizers for photodynamic therapy.

Acknowledgements

The authors acknowledge HBUST and the Key Laboratory of Photochemistry, Chinese Academy of Sciences, for funding the present project.

References

Substituted Phosphorous Triazatetrabenzocorroles: Correlation Between Structure and Excited State Properties

Abstract

Acknowledgements

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