Modulating TTA efficiency through control of high energy triplet states

Carrod, Andrew J.; Cravcenco, Alexei; Ye, Chen; Börjesson, Karl

doi:10.1039/d1tc05292f

Cited by 12 publications

(25 citation statements)

References 53 publications

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“…For example, the peak absorption wavelengths of unsubstituted perylene in the nonpolar solvent toluene is ~438 nm (see, e.g., refs. [ 24 , 30 ]) and in the polar solvent acetonitrile is ~434 nm (ref. [ 25 ]).…”

Section: Resultsmentioning

confidence: 99%

“…Taking the energy difference between the lowest-energy absorption and highest-energy fluorescence emission bands (that correspond to the most-intense absorption and fluorescence emission bands), a value of ~420 cm −1 is obtained for the Stokes shift. Literature reports a much smaller Stokes shift of 260 cm −1 for perylene in both acetonitrile and toluene [ 24 , 25 , 29 ]. It is possible that the larger Stokes shift observed in the DNA-templated perylene arises from: (i) a break in the symmetry of perylene with the addition of the ethynyl linker and uracil nucleobase, or (ii) the incorporation of perylene into the DNA HJ nanostructure [ 69 , 70 ].…”

Section: Resultsmentioning

confidence: 99%

“…Perylene is a rigid polycyclic aromatic hydrocarbon with exemplary photophysical properties that make it an ideal candidate for singlet fission. For example, dilute solutions of perylene monomer in toluene and acetonitrile exhibit peak extinction coefficients of 39,000 and 37,000 M −1 cm −1 , respectively, [ 24 , 25 ] in the visible wavelength region. Such appreciable peak extinction coefficients, which can correspond to appreciable transition dipole moment amplitudes, may be beneficial for forming delocalized, collective excitations, i.e., molecular excitons [ 26 , 27 ].…”

Section: Introductionmentioning

confidence: 99%

“…Such appreciable peak extinction coefficients, which can correspond to appreciable transition dipole moment amplitudes, may be beneficial for forming delocalized, collective excitations, i.e., molecular excitons [ 26 , 27 ]. Additionally, in organic solvents such as toluene and acetonitrile, perylene exhibits a fluorescence quantum yield (FQY) of near unity, [ 24 , 28 , 29 ] indicating that perylene in its monomeric form exhibits very little intrinsic nonradiative decay. The minimal nonradiative decay in monomeric perylene is beneficial for singlet fission, as it minimizes parallel competing decay pathways.…”

Section: Introductionmentioning

confidence: 99%

“…In the case of unsubstituted perylene, E S1 = 2.83–2.86 eV (refs. [ 24 , 25 , 30 ]) and E T1 = 1.50 eV (ref. [ 31 ]).…”

Section: Introductionmentioning

confidence: 99%

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Symmetry Breaking Charge Transfer in DNA-Templated Perylene Dimer Aggregates

Duncan

Kellis²,

Huff³

et al. 2022

Molecules

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Molecular aggregates are of interest to a broad range of fields including light harvesting, organic optoelectronics, and nanoscale computing. In molecular aggregates, nonradiative decay pathways may emerge that were not present in the constituent molecules. Such nonradiative decay pathways may include singlet fission, excimer relaxation, and symmetry-breaking charge transfer. Singlet fission, sometimes referred to as excitation multiplication, is of great interest to the fields of energy conversion and quantum information. For example, endothermic singlet fission, which avoids energy loss, has been observed in covalently bound, linear perylene trimers and tetramers. In this work, the electronic structure and excited-state dynamics of dimers of a perylene derivative templated using DNA were investigated. Specifically, DNA Holliday junctions were used to template the aggregation of two perylene molecules covalently linked to a modified uracil nucleobase through an ethynyl group. The perylenes were templated in the form of monomer, transverse dimer, and adjacent dimer configurations. The electronic structure of the perylene monomers and dimers were characterized via steady-state absorption and fluorescence spectroscopy. Initial insights into their excited-state dynamics were gleaned from relative fluorescence intensity measurements, which indicated that a new nonradiative decay pathway emerges in the dimers. Femtosecond visible transient absorption spectroscopy was subsequently used to elucidate the excited-state dynamics. A new excited-state absorption feature grows in on the tens of picosecond timescale in the dimers, which is attributed to the formation of perylene anions and cations resulting from symmetry-breaking charge transfer. Given the close proximity required for symmetry-breaking charge transfer, the results shed promising light on the prospect of singlet fission in DNA-templated molecular aggregates.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…In the case of unsubstituted perylene, E S1 = 2.83–2.86 eV (refs. [ 24 , 25 , 30 ]) and E T1 = 1.50 eV (ref. [ 31 ]).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Symmetry Breaking Charge Transfer in DNA-Templated Perylene Dimer Aggregates

Duncan

Kellis²,

Huff³

et al. 2022

Molecules

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Enhancing Triplet‐Triplet Annihilation Upconversion of Pyrene Derivatives for Photoredox Catalysis via Molecular Engineering

Song,

Liu,

Liu

et al. 2023

Chemistry A European J

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Triplet‐triplet annihilation upconversion (TTA‐UC) has the potential to enhance photoredox catalysis yield. It includes a sensitizer and an annihilator. Efficient and stable annihilators are essential for photoredox catalysis, yet only a few examples are reported. Herein, we designed four novel pyrene annihilators (1, 2, 3 and 4) via introducing aryl‐alkynyl group onto pyrene to systematically modulate their singlet and triplet energies. Coupled with platinum octaethylporphyrin (PtOEP), the TTA‐UC efficiency is enhanced gradually as the number of aryl‐alkynyl group increases. When combining 4 with palladium tetraphenyl‐tetrabenzoporphyrin (PdTPTBP), we achieve the highest red‐to‐green upconversion efficiency (22.4±0.3%) (out of a 50% maximum) so far. Then, this pair is used to activate photooxidation of aryl boronic acid under red light (630 nm), which achieves a great improved reaction yield compared to that activated by green light directly. The result not only provides a design strategy for efficient annihilators, but also shows the advantage of applying TTA‐UC into improving the photoredox catalysis yield.

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Non‐approximative Kinetics of Triplet‐Triplet Annihilation at Room Temperature: Solvent Effects on Delayed Fluorescence

Bjelland,

Nakashima,

Hashimoto

et al. 2023

ChemPhotoChem

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The molecular processes taking place during triplet‐triplet annihilation (TTA) in solvents at room temperature are examined in detail. Special attention is paid to modelling of the nonlinear kinetic reactions. Using time‐ and spectrally resolved spectroscopy of DPA and Pt/Pd‐OEP based sensitizer and annihilators, it is shown how the kinetic of parameters, such as the triplet energy transfer (TET) and TTA of the rate‐reactions, can be simulated, measured and fitted, without approximations, using a numerical scheme. Studies of DPA in the solvents DMSO, THF and toluene at room temperature revealed that viscosity/diffusion together with the excited triplet lifetime of the annihilator are the most crucial parameters for high TTA induced delayed fluorescence. From an analysis of the experimentally determined rates an efficiency of 16–40 % was determined for the combined TET and TTA processes using THF, DMSO and toluene as solvents. (DPA=9,10‐diphenylanthracene, OEP=2,3,7,8,12,13,17,18‐octaethyl‐21H,23H‐porphyrin)

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Modulating TTA efficiency through control of high energy triplet states

Abstract: An ideal annihilator in triplet-triplet annihilation photon upconversion (TTA-UC) can achieve a maximum of 50% quantum efficiency. This spin statistical limit depends on the energies of triplet states of the...

Cited by 12 publications

References 53 publications

Symmetry Breaking Charge Transfer in DNA-Templated Perylene Dimer Aggregates

Symmetry Breaking Charge Transfer in DNA-Templated Perylene Dimer Aggregates

Enhancing Triplet‐Triplet Annihilation Upconversion of Pyrene Derivatives for Photoredox Catalysis via Molecular Engineering

Non‐approximative Kinetics of Triplet‐Triplet Annihilation at Room Temperature: Solvent Effects on Delayed Fluorescence

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