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. 2024 Sep 18;2(10):539–544. doi: 10.1021/prechem.4c00050

Triplet–Triplet Annihilation-Based Photon Upconversion with a Macrocyclic Parallel Dimer

Catherine H Mulyadi †, Masanori Uji †, Bhavesh Parmar †,‡, Kana Orihashi †, Nobuhiro Yanai †,‡,§,*
PMCID: PMC11522992  PMID: 39483270

Abstract

graphic file with name pc4c00050_0005.jpg

The integration of multiple chromophore units into a single molecule is expected to improve the performance of photon upconversion based on triplet–triplet annihilation (TTA-UC) that can convert low energy photons to higher energy photons at low excitation intensity. In this study, a macrocyclic parallel dimer of 9,10-diphenylanthracene (DPA) with a precisely parallel orientation, named MPD-2, is synthesized, and its TTA-UC properties are investigated. MPD-2 shows a green-to-blue TTA-UC emission in the presence of a triplet sensitizer, platinum octaethylporphyrin (PtOEP). Compared to monomeric DPA, MPD-2 results in an enhancement of the spin statistical factor of TTA and a decrease in the excitation light intensity due to the intramolecular TTA process. The obtained structure–property relationship provides important information for the further improvement of TTA-UC properties.

Keywords: photon upconversion, triplet−triplet annihilation, macrocyclic parallel dimer, spin statistical factor, anthracene

Introduction

Sunlight is one of the most crucial renewable energies in our environment and its effective use is demanded. Photon upconversion is a methodology for converting low energy photons to higher energy ones and has the potential to improve the efficiency of sunlight-powered devices.1,2 Among several UC mechanisms, triplet–triplet annihilation-based photon upconversion (TTA-UC) is particularly attractive due to the possibility of utilizing low intensity, noncoherent light.3−8 The general TTA-UC mechanism is shown in Figure 1. TTA-UC occurs in multichromophore systems: a triplet sensitizer and an emitter. First, the sensitizer molecule is photoexcited from the ground state (S0,S) to the excited singlet state (S1,S), followed by intersystem crossing (ISC) to the excited triplet state (T1,S). Triplet energy transfer (TET) from the sensitizer to emitter is followed by annihilation between two acceptor triplets (T1,E) and generation of an emitter excited singlet state (S1,E).

Figure 1.

Figure 1

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(a) Energy level diagram of TTA-UC. (b) Molecular structures of a sensitizer (PtOEP) and emitters (DPA, MPD-2).

Since the TTA event proceeds based on the Dexter mechanism, it depends on the molecular diffusion of the excited triplet. Therefore, it is necessary to increase the emitter concentration to get the excited triplet closer for an efficient TTA-UC process. However, a high emitter concentration causes undesired phase separation and aggregation, leading to a decrease in the luminescence efficiency.3,9,10 One promising way to mitigate this challenge is to introduce multiple emitter sites within a single molecule and allow intramolecular-TTA (intra-TTA) as well as intermolecular-TTA (inter-TTA) events.11−26 The intra-TTA process is independent of molecular diffusion and thus avoids the diffusion limitations of Dexter-type TTA. So far, the intra-TTA process has been focused on emitter molecules with dimer,11,15,16,18,23−26 dendrimer,14,17,19 and polymer structures.12,13,21,22 In several recent studies, various dimer molecules based on diphenylanthracene (DPA) have been studied to investigate the effect of chromophore structure on TTA-UC.11,15,16,23,24 However, a decrease in the f value, the spin statistical factor for obtaining an excited singlet state after TTA, and an increase in the excitation light intensity required to obtain an efficient TTA-UC emission have been reported relative to those of the DPA monomer. Therefore, the fine-tuning of the dimer structure and deeper understanding of the structure–property relationship are highly desired.

It has been reported that the chromophore structure and orientation of the dimer molecules are crucial for controlling the dynamics of multiexcitonic triplet dimer states in the singlet fission, which is the inverse process of TTA.27−30 Recent simulations have also indicated that parallel orientation in the triplet dimer state could be the key for improving the f value of the TTA-UC process.31 To experimentally address the effect of chromophore orientation on the f value, it is crucial to create an emitter dimer with a parallel orientation.

In this study, a macrocyclic parallel dimer (MPD-2) with two DPA units precisely parallel-oriented has been synthesized, and its TTA-UC properties were investigated. The synthetic procedure follows our previous work, where we synthesized a macrocyclic parallel dimer with pentacene chromophores (MPD-1).32 The TTA-UC properties of MPD-2 were compared to those of a DPA monomer by utilizing platinum octaethylporphyrin (PtOEP) as a triplet sensitizer (Figure 1b). MPD-2 showed an increase in the f value and a decrease in excitation light intensity compared with DPA were observed, demonstrating the positive effect of the precisely parallel-oriented chromophore dimer.

Result and Discussion

The synthesis of MPD-2 was performed in two steps (Figure S1). 4,4′-(Anthracene-9,10-diyl)dibenzaldehyde (DPA-2CHO) was synthesized by a Suzuki Miyaura cross-coupling reaction as previously reported.33 DPA-2CHO and m-xylylenediamine were then mixed, and acetic acid was added dropwise as a catalyst. The formation of the Schiff base gave MPD-2 with a yield of 56% (Figure 2a, see the Supporting Information for details). The purity of MPD-2 was fully confirmed by 1H NMR, high-resolution mass spectroscopy (HR-MS), and elemental analysis (Figures S2 and S3).

Figure 2.

Figure 2

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(a) Synthetic scheme and (b) single crystal structure of MPD-2.

Single crystal X-ray diffraction (SCXRD) measurements revealed that the distance between the proximate aromatic rings of two anthracene units is 3.7 Å, indicating the presence of π–π interactions (Figure 2b, see the Supporting Information for details). The interplanar angle between the two anthracene units was found to be 0°, indicating a precisely parallel orientation.

The absorption and emission spectra of DPA, MPD-2, and PtOEP in chloroform are shown in Figure 3. The molar absorption coefficient of MPD-2 is about 1.6 times that of DPA, consistent with the property of DPA dimers as previously reported.23,24 The absorption peaks of MPD-2 at 358, 377, and 397 nm showed a slight red shift compared to those of DPA at 357, 375, and 396 nm. The emission spectrum of MPD-2 was observed to be red-shifted compared to that of DPA, resulting in the disappearance of the vibrational structure. The fluorescence quantum yield (ΦFL) and fluorescence lifetime (τFL) of MPD-2 were 61.1% and 4.7 ns, both of which were decreased compared to the monomer (ΦFL = 98.0%, τFL = 7.7 ns, Figure S4). These results indicate an increased nonradiative rate constant from the excited singlet state due to electronic interactions between DPA chromophores (Table S2). The excited triplet energy level of DPA is reported to be 1.77 eV.34 The sensitizer PtOEP has been used in various green-to-blue TTA-UC systems in combination with DPA due to its strong absorption properties above 500 nm and high intersystem crossing efficiency (ΦISC ∼ 100%).5,35−37 The reabsorption of the TTA-UC emission can be suppressed due to the weak absorption of PtOEP at 400–500 nm, where DPA exhibits emission. The T1 energy level of PtOEP is estimated from the 0–0 emission peak in the phosphorescence spectrum to be 1.92 eV, which is high enough to efficiently sensitize a DPA unit.

Figure 3.

Figure 3

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Absorption (solid) and photoluminescence (dashed) spectra of DPA (black), MPD-2 (blue), and PtOEP (red) in chloroform ([DPA] = 20 μM, [MPD-2] = 10 μM, [PtOEP] = 10 μM).

There are two TTA pathways, intermolecular- and intramolecular-TTA (inter-TTA and intra-TTA). The intra-TTA pathway has been reported to predominate when an emitter’s concentration is low relative to a sensitizer.24 Therefore, the TTA-UC characterization were performed on samples with different emitter concentrations. The concentration of PtOEP was fixed at 10 μM, and the concentration ratios of the emitter/sensitizer unit ([E]/[S]) were determined to be 25 and 2, respectively. The further increase of the emitter concentration was difficult due to the solubility limitation of MPD-2. The molecular dispersion of MPD-2 up to 125 μM was confirmed from a Beer–Lambert plot (Figure S5).

Under the irradiation of a 532 nm laser to PtOEP/DPA or PtOEP/MPD-2 mixed solution in deaerated chloroform, blue upconverted emissions were observed (Figure 4a and Figure S6). The millisecond-scale delayed emission supports the triplet-mediated mechanism (Figure S7). The TTA-UC efficiency (ηUC, theoretical maximum: 100%) was determined by the relative method (see Supporting Information for details) to be 17.5% for DPA and 11.9% for MPD-2 when [E]/[S] was 25, and 4.6% for DPA and 3.7% for MPD-2 when [E]/[S] was 2, respectively (Figure 4b). The ηUC can be expressed as the product of the efficiency of each process and is given by the following equation,5,38

graphic file with name pc4c00050_m001.jpg

where f is the spin statistical factor of obtaining an excited singlet state (S1,E) after TTA, ΦISC, ΦTET, ΦTTA, and ΦFL are the quantum yields of ISC, TET, TTA, and emitter fluorescence, respectively. Each of the parameters determining ηUC is summarized in Table 1. The TET efficiency (ΦTET) from PtOEP to DPA or MPD-2 was obtained by phosphorescence quenching experiments according to the following equation,

graphic file with name pc4c00050_m002.jpg

where ΦPL and ΦPL,0 are the phosphorescence quantum yields of sensitizer in the presence or absence of an emitter, respectively. The ΦTET values from PtOEP to DPA and MPD-2 were over 90% at the [E]/[S] ratio of 25 and decreased at the [E]/[S] ratio of 2 (Table 1). The ΦTET was slightly reduced for MPD-2 compared to that for DPA. This is due to the larger molecular size of MPD-2 compared to that of the DPA monomer, which results in slower diffusion dynamics. By increasing the MPD-2 concentration from 10 to 125 μM, the ΦFL value slightly decreased due to the self-absorption. While the ΦTTA value is assumed to be unity in the region well above the threshold excitation intensity (Ith),39 the triplet back energy transfer may take place at low emitter concentration conditions. In addition, under low emitter concentration conditions, the number of emitters available for triplet energy transfer may decrease due to saturation of the emitter triplet as the excitation light intensity increases.5 Therefore, it should be noted that, under low emitter concentration conditions, the f value may be underestimated for both DPA and MPD-2 due to the triplet back energy transfer and decrease in the ΦTET caused by the saturation effect.

Figure 4.

Figure 4

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(a) TTA-UC emission spectra, (b) TTA-UC efficiency (ηUC), (c, d) excitation intensity dependence of UC emission intensity of PtOEP/DPA and PtOEP/MPD-2 in deaerated chloroform ([PtOEP] = 10 μM, [DPA] = 250 or 20 μM, [MPD-2] = 125 or 10 μM, λex = 532 nm, 532 nm notch filter, under Ar).

Table 1. Parameters Relevant to the ηUC and Ith of PtOEP/DPA and PtOEP/MPD-2 ([PtOEP] = 10 μM).

Sample ηUC(%) ΦTET(%) ΦFL(%) fall(%) finter(%) fintra(%) Ith(mW cm–2) ΦISC(%) γTT(10–12 cm3 s–1) τT(ms)
PtOEP/DPA ([DPA] = 250 μM) 16.2 ± 1.3 97.0 97.4 17.1 ± 1.4 17.1 ± 1.4 - 19.5 ∼100 5.7 3.1
PtOEP/MPD-2 ([MPD-2] = 125 μM) 11.6 ± 0.3 94.2 57.2 21.5 ± 0.6 17.1a 23.7 ± 0.9 64.6 ∼100 10.1 1.3
PtOEP/DPA ([DPA] = 20 μM) 4.5 ± 0.08 71.6 98.0 6.4 ± 0.1 6.4 ± 0.1 - 122.5 ∼100 1.5 2.8
PtOEP/MPD-2 ([MPD-2] = 10 μM) 3.65 ± 0.01 52.6 61.1 11.3 ± 0.1 6.4a 13.8 ± 0.05 48.1 ∼100 16.2 1.6
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a

Assuming that the f value derived from the inter-TTA of MPD-2 is similar to that of the DPA monomer.

According to the model reported by Gao and co-workers, the f values for inter- and intra-TTA processes can be estimated as shown in the following equation, assuming that the f value derived from the inter-TTA of MPD-2 is similar to that of the DPA monomer,16

graphic file with name pc4c00050_m003.jpg

where n represents the number of chromophore units that exist in one molecule. Interestingly, a higher f value was observed in MPD-2 than in the DPA monomer, suggesting that the parallel orientation between chromophores contributes to improving the f value. This might be due to the enhanced mixing between the singlet and quintet states of TT dimer, resulting in the effective use of quintet TT dimer in the formation of the emitter singlet excited state S1,E.31,40 Furthermore, the difference in the f value between DPA and MPD-2 under low emitter concentration conditions ([E]/[S] ratio of 2) was larger than that under high emitter concentration conditions ([E]/[S] ratio of 25). This may be due to the intra-TTA process becoming predominant, as the emitter triplet is more easily saturated.5

In addition to the ηUC, the threshold excitation intensity (Ith) is also one of the key parameters for evaluating the TTA-UC performance and can be expressed by the following equation,39,41,42

graphic file with name pc4c00050_m004.jpg

where α is a sensitizer absorption coefficient, γTT is the rate constant for TTA, and τT is the excited triplet lifetime of an emitter, respectively. In the TTA-UC system, the double log plot of the TTA-UC emission intensity versus excitation intensity changes from quadratic to linear. The Ith is defined as the intersection in the quadratic and linear fitting lines. With an [E]/[S] ratio of 25, the Ith in MPD-2 was 64.8 mW cm–2, higher than the one in the DPA monomer (19.5 mW cm–2), mainly due to the shorter τT (Figure 4c and Figure S7). On the other hand, the Ith in MPD-2 was 48.1 mW cm–2 when the [E]/[S] ratio was 2, which was notably lower than the Ith of 122.5 mW cm–2 in DPA (Figure 4d). Considering the values of ΦTET, γTT, and τT that determine the Ith, the decrease in Ith in MPD-2 is due to the increase in γTT, highlighting the significance of the intra-TTA process (Table 1). The results indicate that the intra-TTA process within a precisely parallel oriented dimer is beneficial not only in improving the f value but also in lowering the Ith. The intra-TTA process is particularly promising for solid-state systems with limited molecular diffusion. However, the low photostability of MPD-2 in the solid state is a challenge. The development of high-performance solid-state UC materials based on the intra-TTA process remains as an important future task.

In conclusion, a macrocyclic parallel dimer with two DPA units was synthesized, and its optical and TTA-UC properties were evaluated. Single crystal X-ray structure analysis of MPD-2 confirmed the parallel interplanar orientation. MPD-2 showed a higher spin statistical factor (f) and lower threshold excitation light intensity (Ith) than the DPA monomer, indicating that the intramolecular TTA process between parallel oriented chromophores could be beneficial for improving the TTA-UC performance. Our results indicate the importance of controlling the orientation between excitons in the TTA process and could provide an improved molecular design for emitters.

Acknowledgments

This work was partly supported by the JST START (JPMJSF2303), JSPS KAKENHI (JP23H00304, JP22KF0295, JP23KJ1717), Kyushu University Platform of Inter-/Transdisciplinary Energy Research (Q-PIT) through its “Module-Research Program”, and Kyushu University Integrated Initiative for Designing Future Society.

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/prechem.4c00050.

  • Experimental procedures and characterization for all compounds; synthetic, spectroscopic, and general methods (PDF)

  • Crystallographic data for MPD-2 (CIF)

Author Contributions

# C.H.M. and M.U. contributed equally to this work.

The authors declare no competing financial interest.

Supplementary Material

pc4c00050_si_001.pdf (1.6MB, pdf)
pc4c00050_si_002.cif (1.2MB, cif)

References

  1. Gholizadeh E. M.; Prasad S. K. K.; Teh Z. L.; Ishwara T.; Norman S.; Petty A. J. II; Cole J. H.; Cheong S.; Tilley R. D.; Anthony J. E.; Huang S.; Schmidt T. W. Photochemical upconversion of near-infrared light from below the silicon bandgap. Nat. Photonics 2020, 14, 585–590. 10.1038/s41566-020-0664-3. [DOI] [Google Scholar]
  2. Albinsson B.; Olesund A. Untapping solar energy resources. Nat. Photonics 2020, 14, 528–530. 10.1038/s41566-020-0681-2. [DOI] [Google Scholar]
  3. Gray V.; Moth-Poulsen K.; Albinsson B.; Abrahamsson M. Towards efficient solid-state triplet-triplet annihilation based photon upconversion: Supramolecular, macromolecular and self-assembled systems. Coord. Chem. Rev. 2018, 362, 54–71. 10.1016/j.ccr.2018.02.011. [DOI] [Google Scholar]
  4. Singh-Rachford T. N.; Castellano F. N. Photon upconversion based on sensitized triplet-triplet annihilation. Coord. Chem. Rev. 2010, 254, 2560–2573. 10.1016/j.ccr.2010.01.003. [DOI] [Google Scholar]
  5. Monguzzi A.; Tubino R.; Hoseinkhani S.; Campione M.; Meinardi F. Low power, non-coherent sensitized photon up-conversion: modelling and perspectives. Phys. Chem. Chem. Phys. 2012, 14, 4322–4332. 10.1039/c2cp23900k. [DOI] [PubMed] [Google Scholar]
  6. Baluschev S.; Miteva T.; Yakutkin V.; Nelles G.; Yasuda A.; Wegner G. Up-Conversion Fluorescence: Noncoherent Excitation by Sunlight. Phys. Rev. Lett. 2006, 97, 143903. 10.1103/PhysRevLett.97.143903. [DOI] [PubMed] [Google Scholar]
  7. Uji M.; Zähringer T. J. B.; Kerzig C.; Yanai N. Visible-to-UV Photon Upconversion: Recent Progress in New Materials and Applications. Angew. Chem., Int. Ed. 2023, 62, e202301506 10.1002/anie.202301506. [DOI] [PubMed] [Google Scholar]
  8. Della Sala P.; Capobianco A.; Caruso T.; Talotta C.; De Rosa M.; Neri P.; Peluso A.; Gaeta C. An Anthracene-Incorporated [8]Cycloparaphenylene Derivative as an Emitter in Photon Upconversion. J. Org. Chem. 2018, 83, 220–227. 10.1021/acs.joc.7b02590. [DOI] [PubMed] [Google Scholar]
  9. Islangulov R. R.; Lott J.; Weder C.; Castellano F. N. Noncoherent Low-Power Upconversion in Solid Polymer Films. J. Am. Chem. Soc. 2007, 129, 12652–12653. 10.1021/ja075014k. [DOI] [PubMed] [Google Scholar]
  10. Karpicz R.; Puzinas S.; Gulbinas V.; Vakhnin A.; Kadashchuk A.; Rand B. P. Exciton dynamics in an energy up-converting solid state system based on diphenylanthracene doped with platinum octaethylporphyrin. Chem. Phys. 2014, 429, 57–62. 10.1016/j.chemphys.2013.12.004. [DOI] [Google Scholar]
  11. Gao C.; Seow J. Y.; Zhang B.; Hall C. R.; Tilley A. J.; White J. M.; Smith T. A.; Wong W. W. H. Tetraphenylethene 9,10-Diphenylanthracene Derivatives - Synthesis and Photophysical Properties. ChemPlusChem. 2019, 84, 746–753. 10.1002/cplu.201900100. [DOI] [PubMed] [Google Scholar]
  12. Lee S. H.; Ayer M. A.; Vadrucci R.; Weder C.; Simon Y. C. Light upconversion by triplet-triplet annihilation in diphenylanthracene-based copolymers. Polym. Chem. 2014, 5, 6898–6904. 10.1039/C4PY00920G. [DOI] [Google Scholar]
  13. Yu X.; Cao X.; Chen X.; Ayres N.; Zhang P. Triplet-triplet annihilation upconversion from rationally designed polymeric emitters with tunable inter-chromophore distances. Chem. Commun. 2015, 51, 588–591. 10.1039/C4CC07589G. [DOI] [PubMed] [Google Scholar]
  14. Börjesson K.; Gilbert M.; Dzebo D.; Albinsson B.; Moth-Poulsen K. Conjugated anthracene dendrimers with monomer-like fluorescence. RSC Adv. 2014, 4, 19846–19850. 10.1039/C4RA02341B. [DOI] [Google Scholar]
  15. Kanoh M.; Matsui Y.; Honda K.; Kokita Y.; Ogaki T.; Ohta E.; Ikeda H. Elongation of Triplet Lifetime Caused by Intramolecular Energy Hopping in Diphenylanthracene Dyads Oriented to Undergo Efficient Triplet-Triplet Annihilation Upconversion. J. Phys. Chem. B 2021, 125, 4831–4837. 10.1021/acs.jpcb.1c01982. [DOI] [PubMed] [Google Scholar]
  16. Gao C.; Prasad S. K. K.; Zhang B.; Dvořák M.; Tayebjee M. J. Y.; McCamey D. R.; Schmidt T. W.; Smith T. A.; Wong W. W. H. Intramolecular Versus Intermolecular Triplet Fusion in Multichromophoric Photochemical Upconversion. J. Phys. Chem. C 2019, 123, 20181–20187. 10.1021/acs.jpcc.9b07098. [DOI] [Google Scholar]
  17. Dzebo D.; Börjesson K.; Gray V.; Moth-Poulsen K.; Albinsson B. Intramolecular Triplet-Triplet Annihilation Upconversion in 9,10-Diphenylanthracene Oligomers and Dendrimers. J. Phys. Chem. C 2016, 120, 23397–23406. 10.1021/acs.jpcc.6b07920. [DOI] [Google Scholar]
  18. Pun A. B.; Sanders S. N.; Sfeir M. Y.; Campos L. M.; Congreve D. N. Annihilator dimers enhance triplet fusion upconversion. Chem. Sci. 2019, 10, 3969–3975. 10.1039/C8SC03725F. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. He G.; Churchill E. M.; Parenti K. R.; Zhang J.; Narayanan P.; Namata F.; Malkoch M.; Congreve D. N.; Cacciuto A.; Sfeir M. Y.; Campos L. M. Promoting multiexciton interactions in singlet fission and triplet fusion upconversion dendrimers. Nat. Commun. 2023, 14, 6080. 10.1038/s41467-023-41818-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Mattiello S.; Mecca S.; Ronchi A.; Calascibetta A.; Mattioli G.; Pallini F.; Meinardi F.; Beverina L.; Monguzzi A. Diffusion-Free Intramolecular Triplet-Triplet Annihilation in Engineered Conjugated Chromophores for Sensitized Photon Upconversion. ACS Energy Lett. 2022, 7, 2435–2442. 10.1021/acsenergylett.2c01224. [DOI] [Google Scholar]
  21. Edhborg F.; Bildirir H.; Bharmoria P.; Moth-Poulsen K.; Albinsson B. Intramolecular Triplet-Triplet Annihilation Photon Upconversion in Diffusionally Restricted Anthracene Polymer. J. Phys. Chem. B 2021, 125, 6255–6263. 10.1021/acs.jpcb.1c02856. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Tilley A. J.; Robotham B. E.; Steer R. P.; Ghiggino K. P. Sensitized non-coherent photon upconversion by intramolecular triplet-triplet annihilation in a diphenylanthracene pendant polymer. Chem. Phys. Lett. 2015, 618, 198–202. 10.1016/j.cplett.2014.11.016. [DOI] [Google Scholar]
  23. Matsui Y.; Kanoh M.; Ohta E.; Ogaki T.; Ikeda H. Triplet-Triplet Annihilation-Photon Upconversion Employing an Adamantane-linked Diphenylanthracene Dyad Strategy. J. Photochem. Photobiol., A 2020, 387, 112107. 10.1016/j.jphotochem.2019.112107. [DOI] [Google Scholar]
  24. Olesund A.; Gray V.; Mårtensson J.; Albinsson B. Diphenylanthracene Dimers for Triplet-Triplet Annihilation Photon Upconversion: Mechanistic Insights for Intramolecular Pathways and the Importance of Molecular Geometry. J. Am. Chem. Soc. 2021, 143, 5745–5754. 10.1021/jacs.1c00331. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Gilligan A. T.; Owens R.; Miller E. G.; Pompetti N. F.; Damrauer N. H. Enhancing NIR-to-visible upconversion in a rigidly coupled tetracene dimer: approaching statistical limits for triplet-triplet annihilation using intramolecular multiexciton states. Chem. Sci. 2024, 15, 1283–1296. 10.1039/D3SC04795D. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Roy I.; Garci A.; Beldjoudi Y.; Young R. M.; Pe D. J.; Nguyen M. T.; Das P. J.; Wasielewski M. R.; Stoddart J. F. Host-Guest Complexation-Mediated Supramolecular Photon Upconversion. J. Am. Chem. Soc. 2020, 142, 16600–16609. 10.1021/jacs.0c05445. [DOI] [PubMed] [Google Scholar]
  27. Johnson J. C.; Nozik A. J.; Michl J. The role of Chromophore Coupling in Singlet Fission. Acc. Chem. Res. 2013, 46, 1290–1299. 10.1021/ar300193r. [DOI] [PubMed] [Google Scholar]
  28. Lukman S.; Musser A. J.; Chen K.; Athanasopoulos S.; Yong C. K.; Zeng Z.; Ye Q.; Chi C.; Hodgkiss J. M.; Wu J.; Friend R. H.; Greenham N. C. Tuneable Singlet Exciton Fission and Triplet-Triplet Annihilation in an Orthogonal Pentacene Dimer. Adv. Funct. Mater. 2015, 25, 5452–5461. 10.1002/adfm.201501537. [DOI] [Google Scholar]
  29. Tayebjee M. J. Y.; Sanders S. N.; Kumarasamy E.; Campos L. M.; Sfeir M. Y.; McCamey D. R. Quintet multiexciton dynamics in singlet fission. Nat. Phys. 2017, 13, 182–188. 10.1038/nphys3909. [DOI] [Google Scholar]
  30. Bhattacharyya K.; Datta A. Polymorphism Controlled Singlet Fission in TIPS-Anthracene: Role of Stacking Orientation. J. Phys. Chem. C 2017, 121, 1412–1420. 10.1021/acs.jpcc.6b10075. [DOI] [Google Scholar]
  31. Bossanyi D. G.; Sasaki Y.; Wang S.; Chekulaev D.; Kimizuka N.; Yanai N.; Clark J. Spin Statistics for Triplet-Triplet Annihilation Upconversion: Exchange Coupling, Intermolecular Orientation, and Reverse Intersystem Crossing. JACS Au 2021, 1, 2188–2201. 10.1021/jacsau.1c00322. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Ishii W.; Fuki M.; Bu Ali E. M.; Sato S.; Parmar B.; Yamauchi A.; Mulyadi C. H.; Uji M.; Medina Rivero S.; Watanabe G.; Clark J.; Kobori Y.; Yanai N. A Macrocyclic Parallel Dimer Showing Quantum Coherence of Quintet Multiexcitons at Room Temperature. J. Am. Chem. Soc. 2024, 10.1021/jacs.4c05677. [DOI] [PubMed] [Google Scholar]
  33. Teki Y.; Miyamoto S.; Nakatsuji M.; Miura Y. π-topology and Spin Alignment Utilizing the Excited Molecular Field: Observation of the Excited High-Spin Quartet (S = 3/2) and Quintet (S = 2) States on Purely Organic π-Conjugated Spin Systems. J. Am. Chem. Soc. 2001, 123, 294–305. 10.1021/ja001920k. [DOI] [PubMed] [Google Scholar]
  34. Chattopadhyay S. K.; Kumar C. V.; Das P. K. Triplet-related photophysics of 9,10-diphenylanthracene. A kinetic study of reversible energy transfer from anthracene triplet by nanosecond laser flash photolysis. Chem. Phys. Lett. 1983, 98, 250–254. 10.1016/0009-2614(83)87160-7. [DOI] [Google Scholar]
  35. Khnayzer R. S.; Blumhoff J.; Harrington J. A.; Haefele A.; Deng F.; Castellano F. N. Upconversion-powered photoelectrochemistry. Chem. Commun. 2012, 48, 209–211. 10.1039/C1CC16015J. [DOI] [PubMed] [Google Scholar]
  36. Gray V.; Dzebo D.; Abrahamsson M.; Albinsson B.; Moth-Poulsen K. Triplet-triplet annihilation photon-upconversion: towards solar energy applications. Phys. Chem. Chem. Phys. 2014, 16, 10345–10352. 10.1039/C4CP00744A. [DOI] [PubMed] [Google Scholar]
  37. Schmidt T. W.; Castellano F. N. Photochemical Upconversion: The Primacy of Kinetics. J. Phys. Chem. Lett. 2014, 5, 4062–4072. 10.1021/jz501799m. [DOI] [PubMed] [Google Scholar]
  38. Zhou Y.; Castellano F. N.; Schmidt T. W.; Hanson K. On the Quantum Yield of Photon Upconversion via Triplet-Triplet Annihilation. ACS Energy Lett. 2020, 5, 2322–2326. 10.1021/acsenergylett.0c01150. [DOI] [Google Scholar]
  39. Monguzzi A.; Mezyk J.; Scotognella F.; Tubino R.; Meinardi F. Upconversion-induced fluorescence in multicomponent systems: Steady-state excitation power threshold. Phys. Rev. B 2008, 78, 195112. 10.1103/PhysRevB.78.195112. [DOI] [Google Scholar]
  40. Ha D. G.; Wan R.; Kim C. A.; Lin T. A.; Yang L.; Van Voorhis T.; Baldo M. A.; Dincă M. Exchange controlled triplet fusion in metal-organic frameworks. Nat. Mater. 2022, 21, 1275–1281. 10.1038/s41563-022-01368-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Cheng Y. Y.; Khoury T.; Clady R. G.; Tayebjee M. J.; Ekins-Daukes N. J.; Crossley M. J.; Schmidt T. W. On the efficiency limit of triplet-triplet annihilation for photochemical upconversion. Phys. Chem. Chem. Phys. 2010, 12, 66–71. 10.1039/B913243K. [DOI] [PubMed] [Google Scholar]
  42. Haefele A.; Blumhoff J.; Khnayzer R. S.; Castellano F. N. Getting to the (Square) Root of the Problem: How to Make Noncoherent Pumped Upconversion Linear. J. Phys. Chem. Lett. 2012, 3, 299–303. 10.1021/jz300012u. [DOI] [Google Scholar]

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Supplementary Materials

pc4c00050_si_001.pdf (1.6MB, pdf)
pc4c00050_si_002.cif (1.2MB, cif)

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