Exciton Dynamics of Photoexcited Pendant Porphyrin Polymers in Solution and in Thin Films
| Autor: | Matthew F. Paige, Trevor A. Smith, Jonathan M. White, Wallace W. H. Wong, Ronald P. Steer, Kenneth P. Ghiggino, Amy L. Stevens, Sacha Novakovic |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Quenching (fluorescence) 02 engineering and technology Polymer 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Porphyrin Photon upconversion 0104 chemical sciences chemistry.chemical_compound Fluid solution chemistry Flash photolysis Singlet state Physical and Theoretical Chemistry Thin film 0210 nano-technology |
| Zdroj: | The Journal of Physical Chemistry A. 122:9605-9614 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/acs.jpca.8b09321 |
| Popis: | Several new polymers with rotatable zinc porphyrin pendants have been synthesized and their optical spectroscopic and photophysical properties, including upconversion efficiencies, determined in both fluid solution and thin films. Comparisons made with the β-substituted zinc tetraphenylporphyrin monomers and ZnTPP itself reveal that the yield of triplets resulting from either Q-band or Soret-band excitation of the polymers is surprisingly small. A detailed kinetic analysis of the fluorescence decays and transient triplet absorptions of the substituted monomers and their corresponding polymers reveals that this phenomenon is due to two parallel internal singlet quenching processes assigned to transient intrachain excimer formation. Consequently, the yields of upconverted S2 fluorescence resulting from Q-band excitation in the degassed polymers are significantly diminished in both fluid solution and thin films. Implications of these results for the design of polymer upconverting systems are discussed. |
| Databáze: | OpenAIRE |
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