Rana Mhanna, Julia Berger, Matthias Jourdain, Stephan Muth, Roger Jan Kutta, Gregor Jung
{"title":"激发波长对涤纶单分子光化学的意外影响。","authors":"Rana Mhanna, Julia Berger, Matthias Jourdain, Stephan Muth, Roger Jan Kutta, Gregor Jung","doi":"10.1002/cphc.202400996","DOIUrl":null,"url":null,"abstract":"<p><p>The reaction of terrylene in p-terphenyl with molecular oxygen is reinvestigated by TIRF-microscopy with λ<sub>exc</sub>=488 nm or λ<sub>exc</sub>=561 nm and 488 nm. A similar range of fluorescent products is obtained under both experimental conditions with a reaction quantum yield Φ<sub>r</sub>>10<sup>-7</sup> for those molecules which undergo the photoreaction. The majority of these oxygen-susceptible molecules reacts via an electronically relaxed, dark intermediate, presumably an endoperoxide, with a lifetime of <t<sub>off</sub>>~20 s. From this time constant, an activation energy E<sub>A</sub><0.8 eV is estimated for the transition from the intermediate to the final product, the diepoxide, which nicely agrees with values calculated for the terrylene-derivative TDI. However, ~20 % of all reacting molecules at λ<sub>exc</sub>=561 nm and even ~40 % at λ<sub>exc</sub>=488 nm show an immediate change of the fluorescence colour within the time resolution of the experiment, bypassing any dark intermediate. Based on this experimentally observed impact of the excitation energy and the lack of relevant excited-state absorption, we hypothesize that oxygen forms a complex with ground-state terrylene which then undergoes a quasi-unimolecular reaction in the excited-state before vibrational relaxation takes place.</p>","PeriodicalId":9819,"journal":{"name":"Chemphyschem","volume":" ","pages":"e202400996"},"PeriodicalIF":2.3000,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of Excitation Wavelength in Single-Molecule Photochemistry of Terrylene.\",\"authors\":\"Rana Mhanna, Julia Berger, Matthias Jourdain, Stephan Muth, Roger Jan Kutta, Gregor Jung\",\"doi\":\"10.1002/cphc.202400996\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The reaction of terrylene in p-terphenyl with molecular oxygen is reinvestigated by TIRF-microscopy with λ<sub>exc</sub>=488 nm or λ<sub>exc</sub>=561 nm and 488 nm. A similar range of fluorescent products is obtained under both experimental conditions with a reaction quantum yield Φ<sub>r</sub>>10<sup>-7</sup> for those molecules which undergo the photoreaction. The majority of these oxygen-susceptible molecules reacts via an electronically relaxed, dark intermediate, presumably an endoperoxide, with a lifetime of <t<sub>off</sub>>~20 s. From this time constant, an activation energy E<sub>A</sub><0.8 eV is estimated for the transition from the intermediate to the final product, the diepoxide, which nicely agrees with values calculated for the terrylene-derivative TDI. However, ~20 % of all reacting molecules at λ<sub>exc</sub>=561 nm and even ~40 % at λ<sub>exc</sub>=488 nm show an immediate change of the fluorescence colour within the time resolution of the experiment, bypassing any dark intermediate. Based on this experimentally observed impact of the excitation energy and the lack of relevant excited-state absorption, we hypothesize that oxygen forms a complex with ground-state terrylene which then undergoes a quasi-unimolecular reaction in the excited-state before vibrational relaxation takes place.</p>\",\"PeriodicalId\":9819,\"journal\":{\"name\":\"Chemphyschem\",\"volume\":\" \",\"pages\":\"e202400996\"},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2025-01-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemphyschem\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://doi.org/10.1002/cphc.202400996\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemphyschem","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1002/cphc.202400996","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Effect of Excitation Wavelength in Single-Molecule Photochemistry of Terrylene.
The reaction of terrylene in p-terphenyl with molecular oxygen is reinvestigated by TIRF-microscopy with λexc=488 nm or λexc=561 nm and 488 nm. A similar range of fluorescent products is obtained under both experimental conditions with a reaction quantum yield Φr>10-7 for those molecules which undergo the photoreaction. The majority of these oxygen-susceptible molecules reacts via an electronically relaxed, dark intermediate, presumably an endoperoxide, with a lifetime of off>~20 s. From this time constant, an activation energy EA<0.8 eV is estimated for the transition from the intermediate to the final product, the diepoxide, which nicely agrees with values calculated for the terrylene-derivative TDI. However, ~20 % of all reacting molecules at λexc=561 nm and even ~40 % at λexc=488 nm show an immediate change of the fluorescence colour within the time resolution of the experiment, bypassing any dark intermediate. Based on this experimentally observed impact of the excitation energy and the lack of relevant excited-state absorption, we hypothesize that oxygen forms a complex with ground-state terrylene which then undergoes a quasi-unimolecular reaction in the excited-state before vibrational relaxation takes place.
期刊介绍:
ChemPhysChem is one of the leading chemistry/physics interdisciplinary journals (ISI Impact Factor 2018: 3.077) for physical chemistry and chemical physics. It is published on behalf of Chemistry Europe, an association of 16 European chemical societies.
ChemPhysChem is an international source for important primary and critical secondary information across the whole field of physical chemistry and chemical physics. It integrates this wide and flourishing field ranging from Solid State and Soft-Matter Research, Electro- and Photochemistry, Femtochemistry and Nanotechnology, Complex Systems, Single-Molecule Research, Clusters and Colloids, Catalysis and Surface Science, Biophysics and Physical Biochemistry, Atmospheric and Environmental Chemistry, and many more topics. ChemPhysChem is peer-reviewed.