Phosphorescence quenching and flash photolysis experiments demonstrate that photoinduced intra-assembly triplet-triplet energy transfer can take place via a 2-ureido-4[1H]-pyrimidinone-bridged benzophenone-naphthalene assembly I with a rate constant of 3.0 x 106 s-1 and an efficiency of 95% in CH2Cl2. This new finding suggests that with high binding strength and directionality, the 2-ureido-4[1H]-pyrimidinone hydrogen-bonded module may serve as a new model to illustrate the fundamental principles governing the triplet-triplet energy-transfer process through hydrogen bonds.
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http://dx.doi.org/10.1021/jp711807s | DOI Listing |
J Phys Chem A
January 2025
Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States.
Triplet-triplet energy transfer (TEnT) is of particular interest in various photochemical, photobiological, and energy science processes. It involves the exchange of spin and energy of electrons between two molecular fragments. Here, quasi-diabatic self-consistent field solutions were used to obtain the diabatic states involved in TEnT.
View Article and Find Full Text PDFMater Adv
January 2025
Department of Materials Science and Metallurgy, University of Cambridge CB3 0FS UK
The ability to convert light to higher energies through triplet-triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature ( ), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)).
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Pendant organic chromophores have been used to improve the photocatalytic performance of many metal-based photosensitizers, particularly in first-row metals, by increasing π conjugation in ligands and lowering the energy of the photoactive absorption band. Using a combination of spectroscopic studies and computational modeling, we rationalize the excited state dynamics of a Co(III) complex containing pendant pyrene moieties, , where = 1,1'-(4-(pyren-1-yl)pyridine-2,6-diyl)bis(3-methyl-1-imidazol-3-ium). displays higher visible absorptivity, and blue luminescence from pyrene singlet excited states compared with [ = 1,1'-(pyridine-2,6-diyl)bis(3-methyl-1-imidazol-3-ium)] in which the pyrene moiety is absent.
View Article and Find Full Text PDFChemistry
January 2025
School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P. R. China.
Photophysical properties of condensed systems generally originate from collective contributions of all components in their stochastically fluctuated structures and are strongly influenced under strain of chromophores. To precisely identify how the stochastically fluctuated monomers synergistically manipulate the properties, we propose a statistic strategy over sufficient ab initio molecular dynamics (AIMD) samplings and for the first time uncover that synergistic oscillatory twisting (SOT) of neighboring under-strain monomers manipulates the bifunction of rubrene crystal. The under-strain trunk SOT can regulate both singlet fission (SF) and triplet-triplet annihilation (TTA), enabling their coexistence and dominance switching by dynamically modulating the matching of excitation energies.
View Article and Find Full Text PDFSmall
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The ligands in metal-organic framework (MOF) play as light absorption center and transfer photogenerated electrons to metal node through ligand-to-metal charge transfer (LMCT) during photocatalysis, and energy utilization efficiency is strongly restricted by the light inertness of ligands. Herein, a ligand updating strategy is proposed by inserting energy centers to MOFs to activate the inherent ligands, realizing boosting hot electron generation and photocatalytic activities via the cascaded proceeding of energy transfer and charge transfer. By taking PCN-777 (a zeotype mesoporous Zr-containing MOF) as an example, this study shows that the embedded energy center of 1-pyrenecarboxylic acid (PCA) can activate the inherent ligand of PCN-777 through triplet-triplet energy transfer, where triplet excitons would dissociate into photocarriers migrating to the Zr metal cluster via LMCT process.
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