A heavy-atom-free triplet sensitizer suitable for triplet-triplet annihilation-based photon upconversion was developed from the thermally activated delayed fluorescence (TADF) molecule 4CzPN by covalently tethering a pyrene derivative (DBP) as a triplet acceptor. The triplet exciton produced by 4CzPN is captured by the intramolecular pyrenyl acceptor and subsequently transferred via intermolecular triplet-triplet energy transfer (TTET) to freely diffusing pyrenyl acceptors in toluene. Transient absorption and time-resolved photoluminescence spectroscopy were employed to examine the dynamics of both the intra- and intermolecular TTET processes, and the results indicate that the intramolecular energy transfer from 4CzPN to DBP is swift, quantitative, and nearly irreversible. The reverse intersystem crossing is suppressed while intersystem crossing remains efficient, achieving high triplet yield and long triplet lifetime simultaneously. The ultralong excited state lifetime characteristic of the DBP triplet was shown to be crucial for enhancing the intermolecular TTET efficiency and the subsequent triplet-triplet annihilation photochemistry. It was also demonstrated that with the long triplet lifetime of the tethered DBP, TTET was enabled under low free acceptor concentrations and/or with sluggish molecular diffusion in polymer matrixes.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpca.8b05901 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Boosting Light-Driven CO2 Conversion into CO by a Polypyridine Iron(II) Catalyst Using an Organic Sensitizer.
ChemSusChem
January 2025
Universita degli Studi di Ferrara, Dipartimento di Scienze Chimiche e Farmaceutiche, Via Borsari 46, 44121, Ferrara, ITALY.
Direct photochemical conversion of CO2 into a single carbon-based product currently represents one of the major issues in the catalysis of the CO2 reduction reaction (CO2RR). In this work, we demonstrate that the combination of an organic photosensitizer with a heptacoordinated iron(II) complex allows to attain a noble-metal-free photochemical system capable of efficient and selective conversion of CO2 into CO upon light irradiation in the presence of N,N-diisopropylethylamine (DIPEA) and 2,2,2-trifluoroethanol (TFE) as the electron and proton donor, respectively, with unprecedented performances (ΦCO up to 36%, TONCO > 1000, selectivity > 99%). As shown by transient absorption spectroscopy studies, this can be achieved thanks to the fast rates associated with the electron transfer from the photogenerated reduced dye to the catalyst, which protect the dye from parallel degradation pathways ensuring its stability along the photochemical reaction.
View Article and Find Full Text PDF[The many ways flowers send signals to pollinators].
Biol Aujourdhui
January 2025
Institut d'Écologie et des Sciences de l'Environnement de Paris (iEES Paris), Paris, France - Sorbonne Université, 4 place Jussieu, 75005 Paris, France.
The evolutionary success of angiosperms, which make up more than 95 percent of the world's terrestrial flora, is largely based on their interactions with animal pollinators. Indeed, it is estimated that, on average, 87.5 percent of flowering plants are pollinated by animals.
View Article and Find Full Text PDFProbing the Influence of the Protein Scaffold on H-Cluster Reactivity via Gain-of-Function Studies─Improved H Evolution and O Tolerance through Rational Design of [FeFe] Hydrogenase.
J Am Chem Soc
January 2025
Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, P.O. Box 523, Uppsala SE-75120, Sweden.
[FeFe] hydrogenases make up a structurally diverse family of metalloenzymes that catalyze proton/dihydrogen interconversion. They can be classified into phylogenetically distinct groups denoted A-G, which differ in structure and reactivity. Prototypical Group A hydrogenases have high turnover rates and remarkable energy efficiency.
View Article and Find Full Text PDFImpact of Glaciers on Trophic Dynamics and Polyunsaturated Fat Accumulation in Southern Greenland Fjord Ecosystems.
Glob Chang Biol
January 2025
Department of Surface Waters-Research and Management, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.
The primary production of fjords across the Arctic and Subarctic is undergoing significant transformations due to the climatically driven retreat of glaciers and ice sheets. However, the implications of these changes for upper trophic levels remain largely unknown. In this study, we employ both bulk and compound-specific stable isotope analyses to investigate how shifts at the base of fjord food webs impact the carbon and energy sources of consumers.
View Article and Find Full Text PDFBioinspired Superwettability Surface Strategies for Condensation Heat Transfer.
ACS Nano
January 2025
Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China.
Along with the development of miniaturization, integration, and high power of electronic chips in the 5G and artificial intelligence era and their urgent need for technologies enabled to solve high heat flux dissipation in limited space, investigating bioinspired extreme superwettability surfaces with high-efficiency condensation heat transfer (CHT) performance has attracted great interest in academic and industrial communities. Compared with filmwise condensation of flat hydrophilic surfaces featured with continuous liquid films, dropwise condensation of flat hydrophobic surfaces is a more efficient type of energy transport way. However, discrete condensate drops can only shed off the hydrophobic flat surfaces under gravity until their sizes reach the capillary length of liquid, e.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!