Enhancement of two-photon absorption cross section and singlet-oxygen generation in porphyrin-cored star polymers

• 来源期刊: 中国科学B辑(英文版)
• 年，卷（期）: 2009,（1）
• 页码范围: 56-63
• 页数: 8页
• 语种: 英文
• DOI: 10.1007/s11426-008-0157-6

摘要

We report a newly synthesized polymer of a star-shaped porphyrin compound (TPA-FxP) with four oligofiuorene arms at its meso positions with the pronounced enhancement of the two-photon properties and the generation of singlet oxygen by utilizing the two-photon excited fluorescence resonance energy transfer. The steady-state spectra and transient triplet-triplet absorption spectra give evidence that the enhanced two-photon absorption cross section results from not only the through-space energy transfer (Forster) but also the through-bond energy transfer between conjugated peripheral oligofluorene arms and the porphyrin core. The two-photon absorption cross section at 780 nm up to 3360 GM (1 GM = 10-50 cm4.s/photon) of TPA-FxP was obtained, which is comparable to the highest values reported from other similar chemically modified porphyrin core compounds. Furthermore, the enhanced production of singlet oxygen under two-photon absorption conditions is also reported.