Persistent singlet electronic character in the multiexcitonic triplet-pair state of strongly coupled pentacene singlet fission dimers

Atandrita Bhattacharyya; Kanad Majumder; Manish Jain; Namana Venkatareddy; Sanjoy Patra; Satish Patil; Vithoba Hugar; Vivek Tiwari

arxiv: 2606.09130 · v1 · pith:JYPYF4B7new · submitted 2026-06-08 · ⚛️ physics.chem-ph

Persistent singlet electronic character in the multiexcitonic triplet-pair state of strongly coupled pentacene singlet fission dimers

Atandrita Bhattacharyya , Namana Venkatareddy , Sanjoy Patra , Kanad Majumder , Vithoba Hugar , Satish Patil , Manish Jain , Vivek Tiwari This is my paper

Pith reviewed 2026-06-27 14:50 UTC · model grok-4.3

classification ⚛️ physics.chem-ph

keywords singlet fissiontriplet pairpentacene dimerpolarization anisotropysinglet-triplet mixingnear-IR spectroscopy

0 comments

The pith

In pentacene dimers the bound triplet-pair state keeps substantial singlet character throughout its life, so decorrelation loses to decay.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper studies singlet fission in a set of pentacene dimers that differ in their bridging groups. It identifies a near-infrared absorption that appears only after the triplet-pair state forms and then uses time-resolved polarization measurements to follow the electronic makeup of that state. The measurements show that singlet and triplet character remain mixed even after large nuclear motions occur and even when the molecules have time to fluctuate. The same mixing persists no matter which bridge is used. If this holds, the two triplets stay electronically entangled long enough that they recombine before they can separate into independent spin states.

Core claim

Significant singlet-triplet electronic mixing remains present throughout the evolution of the (TT₁)¹ state in strongly coupled pentacene dimers. Once the triplet pair is formed and bound, neither substantial nuclear reorganization nor structural fluctuations on longer timescales suppress this mixing, with the result that triplet-pair decorrelation is outcompeted by decay of the pair itself. The behavior is observed across multiple bridging motifs.

What carries the argument

Polarization anisotropy of the (TT₁)¹-specific near-IR absorption band, used to report the instantaneous singlet-triplet mixing ratio.

If this is right

Triplet-pair decorrelation is slower than the decay channel once the pair is strongly bound.
Polarization-selective pump-probe spectroscopy functions as an optical reporter of decorrelation.
The same persistent mixing occurs for every bridging motif tested.
Planar dimer conformations are required to produce the (TT₁)¹ state.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

Material designs that keep the triplet pair electronically coupled may reduce the yield of free triplets in photovoltaic applications.
The same optical signature could be used to screen new dimers for quantum-information uses that rely on long-lived entangled spin states.
In any strongly coupled multiexciton system, electronic mixing may routinely outrun nuclear-driven decorrelation.

Load-bearing premise

The near-infrared band belongs only to the triplet-pair state and its polarization anisotropy reports the singlet-triplet mixing ratio without major interference from other states or motions.

What would settle it

A clear drop in the near-IR polarization anisotropy on a timescale shorter than the observed decay of the band itself would show that mixing is lost before decay.

Figures

Figures reproduced from arXiv: 2606.09130 by Atandrita Bhattacharyya, Kanad Majumder, Manish Jain, Namana Venkatareddy, Sanjoy Patra, Satish Patil, Vithoba Hugar, Vivek Tiwari.

**Figure 31.** Figure 31: For kinetic analysis of the 2D dataset, we first ignore excitation wavelength dependent (TT1) 1 dynamics, if any. The corresponding RM amplitude for the fastest time constant TSF is shown in [PITH_FULL_IMAGE:figures/full_fig_p009_31.png] view at source ↗

read the original abstract

Singlet fission converts an optically excited singlet state into a spin-entangled triplet pair state (TT$_1$)$^1$ that can, in principle, yield two free triplets for photovoltaics and/or a polarized high spin state for quantum technologies. Synthetically tunable templates suggest that the above photophysics is governed by a subtle but poorly understood interplay of molecular motifs, geometry and structural fluctuations. Here, we investigate the (TT$_1$)$^1$ state in a library of conformationally flexible pentacenic dimers, where a (TT$_1$)$^1$-specific near-IR spectral feature is readily available. Using a suite of polarization-controlled impulsive optical spectroscopies, we find that (TT$_1$)$^1$ formation is specific to planar conformations and is accompanied by large nuclear reorganization in the (TT$_1$)$^1$ photoproduct. Introducing polarization anisotropy to track the electronic character of the (TT$_1$)$^1$ species, supported by screened configuration interaction based electronic structure theory, we find that significant singlet-triplet electronic mixing is persistent throughout its evolution. This behavior is universal across diverse bridging motifs and indicates that, once the triplet pair is strongly bound, neither substantial nuclear reorganization nor structural fluctuations on longer timescales are sufficient to suppress persistent singlet-triplet electronic mixing, such that triplet-pair decorrelation is outcompeted by its decay. Our observations establish polarization-selective pump-probe and anisotropy as a direct optical probe of triplet pair decorrelation, complementary to spin-selective measurements at longer timescales.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

Polarization anisotropy is used to argue for persistent singlet-triplet mixing in the bound TT state across pentacene dimers, but the claim rests on unverified isolation of the near-IR signal.

read the letter

The main observation is that in this library of pentacene dimers the triplet-pair state retains substantial singlet electronic character throughout its lifetime, tracked via polarization anisotropy in the near-IR, and that this holds across different bridges even after nuclear reorganization.

The work assembles a set of conformationally flexible dimers and applies polarization-controlled impulsive spectroscopies to a (TT1)1-specific near-IR band. They report that formation occurs only in planar conformations, that large reorganization accompanies the state, and that anisotropy measurements plus screened CI calculations indicate the singlet-triplet mixing does not decay away. The conclusion is that decorrelation is outcompeted by the pair's own decay, giving a new optical handle on the process.

The anisotropy approach itself is a reasonable addition; it offers a way to follow electronic character on ultrafast timescales that complements spin-selective methods at longer delays. The conformation dependence and the claim of universality across bridges are stated clearly.

The soft spot is exactly the one flagged in the stress test. The central claim requires that the near-IR feature belongs exclusively to (TT1)1 and that the anisotropy decay reports only the electronic mixing ratio, without significant contributions from rotational diffusion, overlapping transitions, or conformation-dependent dipole reorientation. The abstract supplies no raw spectra, error bars, or explicit controls for those effects, so it is impossible to judge how cleanly the signal is isolated. If those assumptions hold in the full data the result stands; if they do not, the persistence and universality arguments lose force. The CI calculations are supportive but cannot substitute for experimental isolation.

The paper is aimed at singlet-fission and organic photophysics groups who already work with ultrafast polarization methods. A reader focused on triplet-pair dynamics would find the proposed optical probe worth examining.

It deserves peer review. The experimental direction is worth referee scrutiny even if the signal-origin checks need strengthening.

Referee Report

1 major / 0 minor

Summary. The manuscript examines the (TT₁)¹ triplet-pair state in a library of conformationally flexible pentacene singlet-fission dimers. It reports that (TT₁)¹ formation occurs only in planar conformations and is accompanied by substantial nuclear reorganization. Polarization anisotropy measurements, supported by screened configuration-interaction calculations, are used to conclude that significant singlet–triplet electronic mixing persists throughout the evolution of the bound (TT₁)¹ state, independent of nuclear reorganization or structural fluctuations, and that this behavior is universal across diverse bridging motifs; consequently, triplet-pair decorrelation is outcompeted by decay. Polarization-selective pump–probe and anisotropy are proposed as a direct optical probe of decorrelation, complementary to spin-selective methods.

Significance. If the central interpretation holds, the work supplies an optical handle on the electronic character of the bound triplet pair that is complementary to EPR or other spin-selective techniques at longer times. The claimed universality across bridging motifs would constrain models of how geometry and fluctuations control singlet–triplet mixing in strongly coupled dimers, with direct relevance to singlet-fission photovoltaics and to the generation of polarized high-spin states.

major comments (1)

[anisotropy analysis and near-IR band assignment] The load-bearing step is the attribution of the observed near-IR polarization anisotropy decay exclusively to the decay of singlet–triplet mixing within (TT₁)¹. The manuscript must demonstrate, with explicit controls or supporting data, that the near-IR band is free of overlapping electronic transitions, that rotational diffusion on the experimental timescale does not contribute appreciably, and that conformation-dependent reorientation of transition dipoles has been ruled out; without such isolation the universality claim across bridging motifs cannot be secured.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading and constructive major comment. We address it point-by-point below and will revise the manuscript to make the supporting controls more explicit.

read point-by-point responses

Referee: [anisotropy analysis and near-IR band assignment] The load-bearing step is the attribution of the observed near-IR polarization anisotropy decay exclusively to the decay of singlet–triplet mixing within (TT₁)¹. The manuscript must demonstrate, with explicit controls or supporting data, that the near-IR band is free of overlapping electronic transitions, that rotational diffusion on the experimental timescale does not contribute appreciably, and that conformation-dependent reorientation of transition dipoles has been ruled out; without such isolation the universality claim across bridging motifs cannot be secured.

Authors: We agree that explicit isolation of these factors strengthens the interpretation. The manuscript already supports the near-IR band assignment via its exclusive appearance in planar conformations, matching kinetics to the (TT₁)¹ decay, and direct agreement with screened CI calculations for energies and polarizations of the mixed state (see main text and SI). Overlapping transitions are ruled out by the absence of other features in the selected spectral window and by comparison to monomer controls. Rotational diffusion is negligible on the sub-ns experimental timescale, as the molecular hydrodynamic radius yields rotational correlation times ≫10 ns in the solvents used. Conformation-dependent dipole reorientation is inconsistent with the calculations, which show stable transition-dipole orientations for the planar (TT₁)¹ geometries across all bridges studied. The universality claim rests on the consistent anisotropy decay behavior observed for the full library. To address the referee’s request for explicit demonstration, the revised manuscript will add a dedicated paragraph with these controls, including calculated dipole vectors and Stokes–Einstein estimates. revision: yes

Circularity Check

0 steps flagged

No significant circularity in derivation chain

full rationale

The paper's central claim rests on experimental polarization anisotropy data interpreted via screened CI electronic structure calculations. No equations, fitted parameters, or self-citations are presented that reduce any prediction or result to its inputs by construction. The derivation chain is self-contained, with observables treated as independent inputs to the interpretation.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the assumption that the observed near-IR feature and anisotropy signal arise solely from the (TT1)1 state and that screened configuration interaction calculations accurately capture the singlet-triplet mixing; no free parameters or new entities are introduced in the abstract.

axioms (1)

standard math Standard assumptions underlying screened configuration interaction electronic structure calculations for molecular excited states.
Invoked to support the interpretation of persistent singlet-triplet mixing.

pith-pipeline@v0.9.1-grok · 5850 in / 1173 out tokens · 22157 ms · 2026-06-27T14:50:47.559696+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

72 extracted references · 39 canonical work pages

[1]

Smith, M. B. & Michl, J. Recent advances in singlet fission.Annual Review of Physical Chemistry64, 361–386 (2013). URL https://www.annualreviews.org/ content/journals/10.1146/annurev-physchem-040412-110130

work page doi:10.1146/annurev-physchem-040412-110130 2013
[2]

Smyser, K. E. & Eaves, J. D. Singlet fission for quantum information and quantum computing: the parallel JDE model.Scientific Reports10, 18480 (2020)

2020
[3]

D., Smyser, K

Dill, R. D., Smyser, K. E., Rugg, B. K., Damrauer, N. H. & Eaves, J. D. Entangled spin-polarized excitons from singlet fission in a rigid dimer.Nature Communications14, 1180 (2023)

2023
[4]

Kawashima, Y.et al.Singlet fission as a polarized spin generator for dynamic nuclear polarization.Nature Communications14, 1–13 (2023)

2023
[5]

V.; Pompetti, N

Korovina, N. V., Pompetti, N. F. & Johnson, J. C. Lessons from intramolecular singlet fission with covalently bound chromophores.The Journal of Chemical Physics152, 040904 (2020). URL https://doi.org/10.1063/1.5135307

work page doi:10.1063/1.5135307 2020
[6]

C., Hybertsen, M

Berkelbach, T. C., Hybertsen, M. S. & Reichman, D. R. Microscopic theory of singlet exciton fission . II . Application to pentacene dimers and the role of superexchange.Journal of Chemical Physics114103(2014)

2014
[7]

& Zhu, X.-Y

Monahan, N. & Zhu, X.-Y. Charge transfer–mediated singlet fission.Annual Review of Physical Chemistry66, 601–618 (2015). URL https://www. annualreviews.org/content/journals/10.1146/annurev-physchem-040214-121235

work page doi:10.1146/annurev-physchem-040214-121235 2015
[8]

M., Johnson, J

Grumstrup, E. M., Johnson, J. C. & Damrauer, N. H. Enhanced triplet for- mation in polycrystalline tetracene films by femtosecond optical-pulse shaping. Phys. Rev. Lett.105, 257403 (2010). URL https://link.aps.org/doi/10.1103/ 36 PhysRevLett.105.257403

2010
[9]

C., Subotnik, J

Alguire, E. C., Subotnik, J. E. & Damrauer, N. H. Exploring non-condon effects in a covalent tetracene dimer: How important are vibrations in determining the electronic coupling for singlet fission?The Journal of Physical Chemistry A119, 299–311 (2015). URL https://doi.org/10.1021/jp510777c. PMID: 25522781

work page doi:10.1021/jp510777c 2015
[10]

A.et al.Real-time observation of multiexcitonic states in ultrafast singlet fission using coherent 2d electronic spectroscopy.Nature Chemistry8, 16–23 (2016)

Bakulin, A. A.et al.Real-time observation of multiexcitonic states in ultrafast singlet fission using coherent 2d electronic spectroscopy.Nature Chemistry8, 16–23 (2016). URL https://doi.org/10.1038/nchem.2371

work page doi:10.1038/nchem.2371 2016
[11]

G.et al.A direct mechanism of ultrafast intramolecular singlet fission in pentacene dimers.ACS Central Science2, 316–324 (2016)

Fuemmeler, E. G.et al.A direct mechanism of ultrafast intramolecular singlet fission in pentacene dimers.ACS Central Science2, 316–324 (2016). URL https: //doi.org/10.1021/acscentsci.6b00063. PMID: 27280166

work page doi:10.1021/acscentsci.6b00063 2016
[12]

Morrison, A. F. & Herbert, J. M. Evidence for singlet fission driven by vibronic coherence in crystalline tetracene.The Journal of Physical Chemistry Letters 8, 1442–1448 (2017). URL https://doi.org/10.1021/acs.jpclett.7b00230. PMID: 28277682

work page doi:10.1021/acs.jpclett.7b00230 2017
[13]

& Reichman, D

Tempelaar, R. & Reichman, D. R. Vibronic exciton theory of singlet fission. III. How vibronic coupling and thermodynamics promote rapid triplet generation in pentacene crystals.The Journal of Chemical Physics148, 244701 (2018)

2018
[14]

Science Advances6(2020)

Duan, H.-G.et al.Intermolecular vibrations mediate ultrafast singlet fission. Science Advances6(2020). URL https://advances.sciencemag.org/content/6/ 38/eabb0052

2020
[15]

& Tiwari, V

Bhattacharyya, A., Sahu, A., Patra, S. & Tiwari, V. Low- and high-frequency vibrations synergistically enhance singlet exciton fission through robust vibronic resonances.Proceedings of the National Academy of Sciences120, e2310124120 37 (2023)

2023
[16]

M., Avlasevich, Y

M¨ uller, A. M., Avlasevich, Y. S., Schoeller, W. W., M¨ ullen, K. & Bardeen, C. J. Exciton fission and fusion in bis(tetracene) molecules with different covalent linker structures.Journal of the American Chemical Society129, 14240–14250 (2007). URL https://doi.org/10.1021/ja073173y

work page doi:10.1021/ja073173y 2007
[17]

Zirzlmeier, J.et al.Singlet fission in pentacene dimers.Proceedings of the National Academy of Sciences112, 5325–5330 (2015)

2015
[18]

URL https://doi

Kumarasamy, E.et al.Tuning singlet fission inπ-bridge-πchromophores.Journal of the American Chemical Society139, 12488–12494 (2017). URL https://doi. org/10.1021/jacs.7b05204. PMID: 28799752

work page doi:10.1021/jacs.7b05204 2017
[19]

V.et al.Linker-dependent singlet fission in tetracene dimers

Korovina, N. V.et al.Linker-dependent singlet fission in tetracene dimers. Journal of the American Chemical Society140, 10179–10190 (2018). URL https://doi.org/10.1021/jacs.8b04401. PMID: 30016102

work page doi:10.1021/jacs.8b04401 2018
[20]

URL https: //doi.org/10.1021/jacs.3c06075

Majumder, K.et al.Controlling intramolecular singlet fission dynamics via torsional modulation of through-bond versus through-space couplings.Jour- nal of the American Chemical Society145, 20883–20896 (2023). URL https: //doi.org/10.1021/jacs.3c06075. PMID: 37705333

work page doi:10.1021/jacs.3c06075 2023
[21]

URL https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202408615

Majumder, K.et al.The acetylene bridge in intramolecular singlet fission: A boon or a nuisance?Angewandte Chemie International Edition63, e202408615 (2024). URL https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202408615

work page doi:10.1002/anie.202408615 2024
[22]

URL https://www

Kim, W.et al.Heterogeneous singlet fission in a covalently linked pentacene dimer.Cell Reports Physical Science5, 102045 (2024). URL https://www. sciencedirect.com/science/article/pii/S266638642400314X. 38

2024
[23]

Sci.13, 11506–11512 (2022)

Bansal, D.et al.A highly contorted push–pull naphthalenediimide dimer and evidence of intramolecular singlet exciton fission.Chem. Sci.13, 11506–11512 (2022)

2022
[24]

Nature Communications9, 4222 (2018)

Lubert-Perquel, D.et al.Identifying triplet pathways in dilute pentacene films. Nature Communications9, 4222 (2018)

2018
[25]

The Journal of Physical Chemistry Letters9, 3354–3360 (2018)

Sakai, H.et al.Multiexciton dynamics depending on intramolecular orientations in pentacene dimers: Recombination and dissociation of correlated triplet pairs. The Journal of Physical Chemistry Letters9, 3354–3360 (2018)

2018
[26]

T., Miller, E

Gilligan, A. T., Miller, E. G., Sammakia, T. & Damrauer, N. H. Using structurally well-defined norbornyl-bridged acene dimers to map a mechanistic landscape for correlated triplet formation in singlet fission.Journal of the American Chemi- cal Society141, 5961–5971 (2019). URL https://doi.org/10.1021/jacs.9b00904. PMID: 30888804

work page doi:10.1021/jacs.9b00904 2019
[28]

Proceedings of the National Academy of Sciences116, 8178–8183 (2019)

Chen, M.et al.Quintet-triplet mixing determines the fate of the multiexciton state produced by singlet fission in a terrylenediimide dimer at room temperature. Proceedings of the National Academy of Sciences116, 8178–8183 (2019). URL https://www.pnas.org/doi/abs/10.1073/pnas.1820932116

work page doi:10.1073/pnas.1820932116 2019
[29]

Kim, J.et al.Elucidating singlet-fission-born multiexciton dynamics via molecu- lar engineering: A dilution principle extended to quintet triplet pair.Journal of the American Chemical Society146, 10833–10846 (2024). 39

2024
[30]

& Hasobe, T

Kobori, Y., Fuki, M., Nakamura, S. & Hasobe, T. Geometries and terahertz motions driving quintet multiexcitons and ultimate triplet–triplet dissociations via the intramolecular singlet fissions.The Journal of Physical Chemistry B124, 9411–9419 (2020)

2020
[31]

Chlan, K

Pabst, M. & K¨ ohn, A. Implementation of transition moments between excited states in the approximate coupled-cluster singles and doubles model.The Jour- nal of Chemical Physics129, 214101 (2008). URL https://doi.org/10.1063/1. 3023118

work page doi:10.1063/1 2008
[32]

URL https://doi.org/10.1063/1.3677839

Anger, F.et al.Photoluminescence spectroscopy of pure pentacene, perfluoropen- tacene, and mixed thin films.The Journal of Chemical Physics136, 054701 (2012). URL https://doi.org/10.1063/1.3677839

work page doi:10.1063/1.3677839 2012
[33]

& Shukla, A

Chakraborty, H. & Shukla, A. Theory of triplet optical absorption in oligoacenes: From naphthalene to heptacene.The Journal of Chemical Physics141, 164301 (2014). URL https://doi.org/10.1063/1.4897955

work page doi:10.1063/1.4897955 2014
[34]

Rao, A., Wilson, M. W. B., Albert-Seifried, S., Di Pietro, R. & Friend, R. H. Photophysics of pentacene thin films: The role of exciton fission and heating effects.Phys. Rev. B84, 195411 (2011). URL https://link.aps.org/doi/10.1103/ PhysRevB.84.195411

2011
[35]

& Kobori, Y

Matsuda, S., Oyama, S. & Kobori, Y. Electron spin polarization generated by transport of singlet and quintet multiexcitons to spin-correlated triplet pairs during singlet fissions.Chemical Science11, 2934–2942 (2020)

2020
[36]

Tayebjee, M. J. Y.et al.Quintet multiexciton dynamics in singlet fission.Nature Physics13, 182–188 (2017). 40

2017
[37]

Hetzer, C., Guldi, D. M. & Tykwinski, R. R. Pentacene dimers as a critical tool for the investigation of intramolecular singlet fission.Chemistry – A Euro- pean Journal24, 8245–8257 (2018). URL https://chemistry-europe.onlinelibrary. wiley.com/doi/abs/10.1002/chem.201705355

work page doi:10.1002/chem.201705355 2018
[38]

URL https://doi.org/10.1021/acs.jpclett.2c01395

Papadopoulos, I.et al.Parallel versus twisted pentacenes: Conformational impact on singlet fission.The Journal of Physical Chemistry Letters13, 5094–5100 (2022). URL https://doi.org/10.1021/acs.jpclett.2c01395. PMID: 35653702

work page doi:10.1021/acs.jpclett.2c01395 2022
[39]

D.et al.Observation of two triplet-pair intermediates in singlet exciton fission.The Journal of Physical Chemistry Letters7, 2370–2375 (2016)

Pensack, R. D.et al.Observation of two triplet-pair intermediates in singlet exciton fission.The Journal of Physical Chemistry Letters7, 2370–2375 (2016). URL https://doi.org/10.1021/acs.jpclett.6b00947. PMID: 27281713

work page doi:10.1021/acs.jpclett.6b00947 2016
[40]

& Mazumdar, S

Khan, S. & Mazumdar, S. Theory of transient excited state absorptions in pen- tacene and derivatives: Triplet–triplet biexciton versus free triplets.The Journal of Physical Chemistry Letters8, 5943–5948 (2017). URL https://doi.org/10. 1021/acs.jpclett.7b02748. PMID: 29164900

2017
[41]

& Mazumdar, S

Khan, S. & Mazumdar, S. Optical probes of the quantum-entangled triplet- triplet state in a heteroacene dimer.Phys. Rev. B98, 165202 (2018). URL https://link.aps.org/doi/10.1103/PhysRevB.98.165202

work page doi:10.1103/physrevb.98.165202 2018
[42]

& Mazumdar, S

Khan, S. & Mazumdar, S. Free triplets versus bound triplet–triplet biexciton in intramolecular singlet fission materials: Structure–property correlations.The Journal of Physical Chemistry C124, 1171–1177 (2020). URL https://doi.org/ 10.1021/acs.jpcc.9b09831

work page doi:10.1021/acs.jpcc.9b09831 2020
[43]

T.et al.Distinct properties of the triplet pair state from singlet fission

Trinh, M. T.et al.Distinct properties of the triplet pair state from singlet fission. Science Advances3, e1700241 (2017). URL https://www.science.org/doi/abs/ 10.1126/sciadv.1700241. 41

work page doi:10.1126/sciadv.1700241 2017
[44]

D.et al.Striking the right balance of intermolecular coupling for high-efficiency singlet fission.Chem

Pensack, R. D.et al.Striking the right balance of intermolecular coupling for high-efficiency singlet fission.Chem. Sci.9, 6240–6259 (2018). URL http://dx. doi.org/10.1039/C8SC00293B

work page doi:10.1039/c8sc00293b 2018
[45]

M., Yang, N

Farrell, K. M., Yang, N. & Zanni, M. T. A polarization scheme that resolves cross- peaks with transient absorption and eliminates diagonal peaks in 2d spectroscopy. Proceedings of the National Academy of Sciences119, e2117398119 (2022). URL https://www.pnas.org/doi/abs/10.1073/pnas.2117398119

work page doi:10.1073/pnas.2117398119 2022
[46]

& Tiwari, V

Sahu, A. & Tiwari, V. Isolating non-adiabatically enhanced ground state quantum beats through two-dimensional electronic spectroscopy.The Journal of Chemical Physics162(2025)

2025
[47]

Venkatareddy, N., Ghosh, V., Krishnamurthy, H. R. & Jain, M. Double excitations in molecules using screened configuration interaction.Journal of Chemical Theory and Computation21, 12162–12171 (2025). URL https://doi.org/10.1021/acs. jctc.5c01484. PMID: 41298140

work page doi:10.1021/acs 2025
[48]

V., Chang, C

Korovina, N. V., Chang, C. H. & Johnson, J. C. Spatial separation of triplet excitons drives endothermic singlet fission.Nature Chemistry12, 391–398 (2020). URL https://doi.org/10.1038/s41557-020-0422-7

work page doi:10.1038/s41557-020-0422-7 2020
[49]

URL https://doi.org/10.1021/acs.jpclett.8b02396

Nagashima, H.et al.Singlet-fission-born quintet state: Sublevel selections and trapping by multiexciton thermodynamics.The Journal of Physical Chemistry Letters9, 5855–5861 (2018). URL https://doi.org/10.1021/acs.jpclett.8b02396

work page doi:10.1021/acs.jpclett.8b02396 2018
[50]

S., Bhat, V

Thomas, A. S., Bhat, V. N. & Tiwari, V. Rapid scan white light two-dimensional electronic spectroscopy with 100 kHz shot-to-shot detection.The Journal of Chemical Physics159, 244202 (2023). 42

2023
[51]

N., Thomas, A

Bhat, V. N., Thomas, A. S., Bhattacharyya, A. & Tiwari, V. Rapid scan white light pump-probe spectroscopy with 100 kHz shot-to-shot detection.Opt. Continuum2, 1981–1995 (2023)

1981
[52]

S.et al.Disordered light-harvesting aggregates can host functional vibronic couplings at room temperature.Nature Communications17, 3127 (2026)

Thomas, A. S.et al.Disordered light-harvesting aggregates can host functional vibronic couplings at room temperature.Nature Communications17, 3127 (2026). URL https://doi.org/10.1038/s41467-026-69815-0

work page doi:10.1038/s41467-026-69815-0 2026
[53]

Marciniak, H.et al.Ultrafast exciton relaxation in microcrystalline pentacene films.Phys. Rev. Lett.99, 176402 (2007). URL https://link.aps.org/doi/10.1103/ PhysRevLett.99.176402

2007
[54]

URL https://doi.org/10.1063/5.0312776

Patra, S.et al.Wavelength-dependent intramolecular singlet fission through an excimer-like intermediate.The Journal of Chemical Physics164, 054201 (2026). URL https://doi.org/10.1063/5.0312776

work page doi:10.1063/5.0312776 2026
[55]

PMID: 31927968

Kim, J.et al.Non-born–oppenheimer molecular dynamics observed by coherent nuclear wave packets.The Journal of Physical Chemistry Letters11, 755–761 (2020). PMID: 31927968

2020
[56]

Heo, W., Lee, C., Sohn, S. H. & Joo, T. Tracking nuclear wave packets in excited- state reactions via quantum mechanics/molecular dynamics simulations.The Journal of Chemical Physics162, 154108 (2025)

2025
[57]

& Petelenz, P

Andrzejak, M., Sk´ ora, T. & Petelenz, P. Is Vibrational Coherence a Byproduct of Singlet Exciton Fission?The Journal of Physical Chemistry C123, 91–101 (2019). URL https://doi.org/10.1021/acs.jpcc.8b09124

work page doi:10.1021/acs.jpcc.8b09124 2019
[58]

& Shukla, A

Sony, P. & Shukla, A. Large-scale correlated calculations of linear optical absorption and low-lying excited states of polyacenes: Pariser-parr-pople hamil- tonian.Phys. Rev. B75, 155208 (2007). URL https://link.aps.org/doi/10.1103/ 43 PhysRevB.75.155208

2007
[59]

D., Haber, J

Folie, B. D., Haber, J. B., Refaely-Abramson, S., Neaton, J. B. & Ginsberg, N. S. Long-lived correlated triplet pairs in a pi-stacked crystalline pentacene derivative.Journal of the American Chemical Society140, 2326–2335 (2018). URL https://doi.org/10.1021/jacs.7b12662. PMID: 29392936

work page doi:10.1021/jacs.7b12662 2018
[60]

K.et al.Morphology effectively controls singlet-triplet exciton relaxation and charge transport in organic semiconductors.Phys

Thorsmølle, V. K.et al.Morphology effectively controls singlet-triplet exciton relaxation and charge transport in organic semiconductors.Phys. Rev. Lett.102, 017401 (2009). URL https://link.aps.org/doi/10.1103/PhysRevLett.102.017401

work page doi:10.1103/physrevlett.102.017401 2009
[61]

A., Smith, E

Farrow, D. A., Smith, E. R., Qian, W. & Jonas, D. M. The polarization anisotropy of vibrational quantum beats in resonant pump-probe experiments: Diagrammatic calculations for square symmetric molecules.Journal of Chemical Physics129, 174509 (2008)

2008
[62]

Nature Chemistry16, 1680–1686 (2024)

Kim, J.et al.Coherent photoexcitation of entangled triplet pair states. Nature Chemistry16, 1680–1686 (2024). URL https://doi.org/10.1038/ s41557-024-01556-3

2024
[63]

Chan Wai-Lun, L. M. & X-Y., Z. The energy barrier in singlet fission can be overcome through coherent coupling and entropic gain.Nature Chemistry4, 840 (2012). URL https://doi.org/10.1038/nchem.1436

work page doi:10.1038/nchem.1436 2012
[64]

S., Nicholas R

Monahan, D. S., Nicholas R. & et al., Z. X.-Y. Dynamics of the triplet-pair state reveals the likely coexistence of coherent and incoherent singlet fission in crystalline hexacene.Nature Chemistry9, 341 (2017). URL https://doi.org/10. 1038/nchem.2665

2017
[65]

URL https://doi.org/10.1021/jacs.7b02621

Breen, I.et al.Triplet separation drives singlet fission after femtosecond correlated triplet pair production in rubrene.Journal of the American Chemical Society 44 139, 11745–11751 (2017). URL https://doi.org/10.1021/jacs.7b02621. PMID: 28763611

work page doi:10.1021/jacs.7b02621 2017
[66]

I., McCamey, D

Collins, M. I., McCamey, D. R. & Tayebjee, M. J. Y. Fluctuating exchange inter- actions enable quintet multiexciton formation in singlet fission.The Journal of Chemical Physics151, 164104 (2019). URL https://doi.org/10.1063/1.5115816

work page doi:10.1063/1.5115816 2019
[67]

I., Campaioli, F., Tayebjee, M

Collins, M. I., Campaioli, F., Tayebjee, M. J. Y., Cole, J. H. & McCamey, D. R. Quintet formation, exchange fluctuations, and the role of stochastic resonance in singlet fission.Communications Physics6, 64 (2023). URL https://doi.org/10. 1038/s42005-023-01177-1

2023
[68]

URL https://doi.org/10.1021/jacs.5c14936

He, G.et al.Bridge connectivity dictates spin interactions and triplet pair dynamics in intramolecular singlet fission.Journal of the American Chemi- cal Society148, 8136–8146 (2026). URL https://doi.org/10.1021/jacs.5c14936. PMID: 41700876

work page doi:10.1021/jacs.5c14936 2026
[69]

The Journal of Chemical Physics , volume =

Jans´ ık, B., Høst, S., Kristensen, K. & Jørgensen, P. Local orbitals by minimizing powers of the orbital variance.The Journal of Chemical Physics134, 194104 (2011). URL https://doi.org/10.1063/1.3590361

work page doi:10.1063/1.3590361 2011
[70]

& Jonas, D

Qian, W. & Jonas, D. M. Role of cyclic sets of transition dipoles in the pump– probe polarization anisotropy: Application to square symmetric molecules and perpendicular chromophore pairs.The Journal of Chemical Physics119, 1611– 1622 (2003)

2003
[71]

S.et al.Unified model for singlet fission within a non-conjugated covalent pentacene dimer.Nature Communications8, 15171 (2017)

Basel, B. S.et al.Unified model for singlet fission within a non-conjugated covalent pentacene dimer.Nature Communications8, 15171 (2017)

2017
[72]

D.et al.Exciton delocalization drives rapid singlet fission in nanopar- ticles of acene derivatives.Journal of the American Chemical Society137, 45 6790–6803 (2015)

Pensack, R. D.et al.Exciton delocalization drives rapid singlet fission in nanopar- ticles of acene derivatives.Journal of the American Chemical Society137, 45 6790–6803 (2015). URL https://doi.org/10.1021/ja512668r. PMID: 25946670

work page doi:10.1021/ja512668r 2015
[73]

Millington, O.et al.The interplay of strongly and weakly exchange-coupled triplet pairs in intramolecular singlet fission.Journal of the American Chemical Society146, 29664–29674 (2024). 46

2024

[1] [1]

Smith, M. B. & Michl, J. Recent advances in singlet fission.Annual Review of Physical Chemistry64, 361–386 (2013). URL https://www.annualreviews.org/ content/journals/10.1146/annurev-physchem-040412-110130

work page doi:10.1146/annurev-physchem-040412-110130 2013

[2] [2]

Smyser, K. E. & Eaves, J. D. Singlet fission for quantum information and quantum computing: the parallel JDE model.Scientific Reports10, 18480 (2020)

2020

[3] [3]

D., Smyser, K

Dill, R. D., Smyser, K. E., Rugg, B. K., Damrauer, N. H. & Eaves, J. D. Entangled spin-polarized excitons from singlet fission in a rigid dimer.Nature Communications14, 1180 (2023)

2023

[4] [4]

Kawashima, Y.et al.Singlet fission as a polarized spin generator for dynamic nuclear polarization.Nature Communications14, 1–13 (2023)

2023

[5] [5]

V.; Pompetti, N

Korovina, N. V., Pompetti, N. F. & Johnson, J. C. Lessons from intramolecular singlet fission with covalently bound chromophores.The Journal of Chemical Physics152, 040904 (2020). URL https://doi.org/10.1063/1.5135307

work page doi:10.1063/1.5135307 2020

[6] [6]

C., Hybertsen, M

Berkelbach, T. C., Hybertsen, M. S. & Reichman, D. R. Microscopic theory of singlet exciton fission . II . Application to pentacene dimers and the role of superexchange.Journal of Chemical Physics114103(2014)

2014

[7] [7]

& Zhu, X.-Y

Monahan, N. & Zhu, X.-Y. Charge transfer–mediated singlet fission.Annual Review of Physical Chemistry66, 601–618 (2015). URL https://www. annualreviews.org/content/journals/10.1146/annurev-physchem-040214-121235

work page doi:10.1146/annurev-physchem-040214-121235 2015

[8] [8]

M., Johnson, J

Grumstrup, E. M., Johnson, J. C. & Damrauer, N. H. Enhanced triplet for- mation in polycrystalline tetracene films by femtosecond optical-pulse shaping. Phys. Rev. Lett.105, 257403 (2010). URL https://link.aps.org/doi/10.1103/ 36 PhysRevLett.105.257403

2010

[9] [9]

C., Subotnik, J

Alguire, E. C., Subotnik, J. E. & Damrauer, N. H. Exploring non-condon effects in a covalent tetracene dimer: How important are vibrations in determining the electronic coupling for singlet fission?The Journal of Physical Chemistry A119, 299–311 (2015). URL https://doi.org/10.1021/jp510777c. PMID: 25522781

work page doi:10.1021/jp510777c 2015

[10] [10]

A.et al.Real-time observation of multiexcitonic states in ultrafast singlet fission using coherent 2d electronic spectroscopy.Nature Chemistry8, 16–23 (2016)

Bakulin, A. A.et al.Real-time observation of multiexcitonic states in ultrafast singlet fission using coherent 2d electronic spectroscopy.Nature Chemistry8, 16–23 (2016). URL https://doi.org/10.1038/nchem.2371

work page doi:10.1038/nchem.2371 2016

[11] [11]

G.et al.A direct mechanism of ultrafast intramolecular singlet fission in pentacene dimers.ACS Central Science2, 316–324 (2016)

Fuemmeler, E. G.et al.A direct mechanism of ultrafast intramolecular singlet fission in pentacene dimers.ACS Central Science2, 316–324 (2016). URL https: //doi.org/10.1021/acscentsci.6b00063. PMID: 27280166

work page doi:10.1021/acscentsci.6b00063 2016

[12] [12]

Morrison, A. F. & Herbert, J. M. Evidence for singlet fission driven by vibronic coherence in crystalline tetracene.The Journal of Physical Chemistry Letters 8, 1442–1448 (2017). URL https://doi.org/10.1021/acs.jpclett.7b00230. PMID: 28277682

work page doi:10.1021/acs.jpclett.7b00230 2017

[13] [13]

& Reichman, D

Tempelaar, R. & Reichman, D. R. Vibronic exciton theory of singlet fission. III. How vibronic coupling and thermodynamics promote rapid triplet generation in pentacene crystals.The Journal of Chemical Physics148, 244701 (2018)

2018

[14] [14]

Science Advances6(2020)

Duan, H.-G.et al.Intermolecular vibrations mediate ultrafast singlet fission. Science Advances6(2020). URL https://advances.sciencemag.org/content/6/ 38/eabb0052

2020

[15] [15]

& Tiwari, V

Bhattacharyya, A., Sahu, A., Patra, S. & Tiwari, V. Low- and high-frequency vibrations synergistically enhance singlet exciton fission through robust vibronic resonances.Proceedings of the National Academy of Sciences120, e2310124120 37 (2023)

2023

[16] [16]

M., Avlasevich, Y

M¨ uller, A. M., Avlasevich, Y. S., Schoeller, W. W., M¨ ullen, K. & Bardeen, C. J. Exciton fission and fusion in bis(tetracene) molecules with different covalent linker structures.Journal of the American Chemical Society129, 14240–14250 (2007). URL https://doi.org/10.1021/ja073173y

work page doi:10.1021/ja073173y 2007

[17] [17]

Zirzlmeier, J.et al.Singlet fission in pentacene dimers.Proceedings of the National Academy of Sciences112, 5325–5330 (2015)

2015

[18] [18]

URL https://doi

Kumarasamy, E.et al.Tuning singlet fission inπ-bridge-πchromophores.Journal of the American Chemical Society139, 12488–12494 (2017). URL https://doi. org/10.1021/jacs.7b05204. PMID: 28799752

work page doi:10.1021/jacs.7b05204 2017

[19] [19]

V.et al.Linker-dependent singlet fission in tetracene dimers

Korovina, N. V.et al.Linker-dependent singlet fission in tetracene dimers. Journal of the American Chemical Society140, 10179–10190 (2018). URL https://doi.org/10.1021/jacs.8b04401. PMID: 30016102

work page doi:10.1021/jacs.8b04401 2018

[20] [20]

URL https: //doi.org/10.1021/jacs.3c06075

Majumder, K.et al.Controlling intramolecular singlet fission dynamics via torsional modulation of through-bond versus through-space couplings.Jour- nal of the American Chemical Society145, 20883–20896 (2023). URL https: //doi.org/10.1021/jacs.3c06075. PMID: 37705333

work page doi:10.1021/jacs.3c06075 2023

[21] [21]

URL https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202408615

Majumder, K.et al.The acetylene bridge in intramolecular singlet fission: A boon or a nuisance?Angewandte Chemie International Edition63, e202408615 (2024). URL https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202408615

work page doi:10.1002/anie.202408615 2024

[22] [22]

URL https://www

Kim, W.et al.Heterogeneous singlet fission in a covalently linked pentacene dimer.Cell Reports Physical Science5, 102045 (2024). URL https://www. sciencedirect.com/science/article/pii/S266638642400314X. 38

2024

[23] [23]

Sci.13, 11506–11512 (2022)

Bansal, D.et al.A highly contorted push–pull naphthalenediimide dimer and evidence of intramolecular singlet exciton fission.Chem. Sci.13, 11506–11512 (2022)

2022

[24] [24]

Nature Communications9, 4222 (2018)

Lubert-Perquel, D.et al.Identifying triplet pathways in dilute pentacene films. Nature Communications9, 4222 (2018)

2018

[25] [25]

The Journal of Physical Chemistry Letters9, 3354–3360 (2018)

Sakai, H.et al.Multiexciton dynamics depending on intramolecular orientations in pentacene dimers: Recombination and dissociation of correlated triplet pairs. The Journal of Physical Chemistry Letters9, 3354–3360 (2018)

2018

[26] [26]

T., Miller, E

Gilligan, A. T., Miller, E. G., Sammakia, T. & Damrauer, N. H. Using structurally well-defined norbornyl-bridged acene dimers to map a mechanistic landscape for correlated triplet formation in singlet fission.Journal of the American Chemi- cal Society141, 5961–5971 (2019). URL https://doi.org/10.1021/jacs.9b00904. PMID: 30888804

work page doi:10.1021/jacs.9b00904 2019

[27] [28]

Proceedings of the National Academy of Sciences116, 8178–8183 (2019)

Chen, M.et al.Quintet-triplet mixing determines the fate of the multiexciton state produced by singlet fission in a terrylenediimide dimer at room temperature. Proceedings of the National Academy of Sciences116, 8178–8183 (2019). URL https://www.pnas.org/doi/abs/10.1073/pnas.1820932116

work page doi:10.1073/pnas.1820932116 2019

[28] [29]

Kim, J.et al.Elucidating singlet-fission-born multiexciton dynamics via molecu- lar engineering: A dilution principle extended to quintet triplet pair.Journal of the American Chemical Society146, 10833–10846 (2024). 39

2024

[29] [30]

& Hasobe, T

Kobori, Y., Fuki, M., Nakamura, S. & Hasobe, T. Geometries and terahertz motions driving quintet multiexcitons and ultimate triplet–triplet dissociations via the intramolecular singlet fissions.The Journal of Physical Chemistry B124, 9411–9419 (2020)

2020

[30] [31]

Chlan, K

Pabst, M. & K¨ ohn, A. Implementation of transition moments between excited states in the approximate coupled-cluster singles and doubles model.The Jour- nal of Chemical Physics129, 214101 (2008). URL https://doi.org/10.1063/1. 3023118

work page doi:10.1063/1 2008

[31] [32]

URL https://doi.org/10.1063/1.3677839

Anger, F.et al.Photoluminescence spectroscopy of pure pentacene, perfluoropen- tacene, and mixed thin films.The Journal of Chemical Physics136, 054701 (2012). URL https://doi.org/10.1063/1.3677839

work page doi:10.1063/1.3677839 2012

[32] [33]

& Shukla, A

Chakraborty, H. & Shukla, A. Theory of triplet optical absorption in oligoacenes: From naphthalene to heptacene.The Journal of Chemical Physics141, 164301 (2014). URL https://doi.org/10.1063/1.4897955

work page doi:10.1063/1.4897955 2014

[33] [34]

Rao, A., Wilson, M. W. B., Albert-Seifried, S., Di Pietro, R. & Friend, R. H. Photophysics of pentacene thin films: The role of exciton fission and heating effects.Phys. Rev. B84, 195411 (2011). URL https://link.aps.org/doi/10.1103/ PhysRevB.84.195411

2011

[34] [35]

& Kobori, Y

Matsuda, S., Oyama, S. & Kobori, Y. Electron spin polarization generated by transport of singlet and quintet multiexcitons to spin-correlated triplet pairs during singlet fissions.Chemical Science11, 2934–2942 (2020)

2020

[35] [36]

Tayebjee, M. J. Y.et al.Quintet multiexciton dynamics in singlet fission.Nature Physics13, 182–188 (2017). 40

2017

[36] [37]

Hetzer, C., Guldi, D. M. & Tykwinski, R. R. Pentacene dimers as a critical tool for the investigation of intramolecular singlet fission.Chemistry – A Euro- pean Journal24, 8245–8257 (2018). URL https://chemistry-europe.onlinelibrary. wiley.com/doi/abs/10.1002/chem.201705355

work page doi:10.1002/chem.201705355 2018

[37] [38]

URL https://doi.org/10.1021/acs.jpclett.2c01395

Papadopoulos, I.et al.Parallel versus twisted pentacenes: Conformational impact on singlet fission.The Journal of Physical Chemistry Letters13, 5094–5100 (2022). URL https://doi.org/10.1021/acs.jpclett.2c01395. PMID: 35653702

work page doi:10.1021/acs.jpclett.2c01395 2022

[38] [39]

D.et al.Observation of two triplet-pair intermediates in singlet exciton fission.The Journal of Physical Chemistry Letters7, 2370–2375 (2016)

Pensack, R. D.et al.Observation of two triplet-pair intermediates in singlet exciton fission.The Journal of Physical Chemistry Letters7, 2370–2375 (2016). URL https://doi.org/10.1021/acs.jpclett.6b00947. PMID: 27281713

work page doi:10.1021/acs.jpclett.6b00947 2016

[39] [40]

& Mazumdar, S

Khan, S. & Mazumdar, S. Theory of transient excited state absorptions in pen- tacene and derivatives: Triplet–triplet biexciton versus free triplets.The Journal of Physical Chemistry Letters8, 5943–5948 (2017). URL https://doi.org/10. 1021/acs.jpclett.7b02748. PMID: 29164900

2017

[40] [41]

& Mazumdar, S

Khan, S. & Mazumdar, S. Optical probes of the quantum-entangled triplet- triplet state in a heteroacene dimer.Phys. Rev. B98, 165202 (2018). URL https://link.aps.org/doi/10.1103/PhysRevB.98.165202

work page doi:10.1103/physrevb.98.165202 2018

[41] [42]

& Mazumdar, S

Khan, S. & Mazumdar, S. Free triplets versus bound triplet–triplet biexciton in intramolecular singlet fission materials: Structure–property correlations.The Journal of Physical Chemistry C124, 1171–1177 (2020). URL https://doi.org/ 10.1021/acs.jpcc.9b09831

work page doi:10.1021/acs.jpcc.9b09831 2020

[42] [43]

T.et al.Distinct properties of the triplet pair state from singlet fission

Trinh, M. T.et al.Distinct properties of the triplet pair state from singlet fission. Science Advances3, e1700241 (2017). URL https://www.science.org/doi/abs/ 10.1126/sciadv.1700241. 41

work page doi:10.1126/sciadv.1700241 2017

[43] [44]

D.et al.Striking the right balance of intermolecular coupling for high-efficiency singlet fission.Chem

Pensack, R. D.et al.Striking the right balance of intermolecular coupling for high-efficiency singlet fission.Chem. Sci.9, 6240–6259 (2018). URL http://dx. doi.org/10.1039/C8SC00293B

work page doi:10.1039/c8sc00293b 2018

[44] [45]

M., Yang, N

Farrell, K. M., Yang, N. & Zanni, M. T. A polarization scheme that resolves cross- peaks with transient absorption and eliminates diagonal peaks in 2d spectroscopy. Proceedings of the National Academy of Sciences119, e2117398119 (2022). URL https://www.pnas.org/doi/abs/10.1073/pnas.2117398119

work page doi:10.1073/pnas.2117398119 2022

[45] [46]

& Tiwari, V

Sahu, A. & Tiwari, V. Isolating non-adiabatically enhanced ground state quantum beats through two-dimensional electronic spectroscopy.The Journal of Chemical Physics162(2025)

2025

[46] [47]

Venkatareddy, N., Ghosh, V., Krishnamurthy, H. R. & Jain, M. Double excitations in molecules using screened configuration interaction.Journal of Chemical Theory and Computation21, 12162–12171 (2025). URL https://doi.org/10.1021/acs. jctc.5c01484. PMID: 41298140

work page doi:10.1021/acs 2025

[47] [48]

V., Chang, C

Korovina, N. V., Chang, C. H. & Johnson, J. C. Spatial separation of triplet excitons drives endothermic singlet fission.Nature Chemistry12, 391–398 (2020). URL https://doi.org/10.1038/s41557-020-0422-7

work page doi:10.1038/s41557-020-0422-7 2020

[48] [49]

URL https://doi.org/10.1021/acs.jpclett.8b02396

Nagashima, H.et al.Singlet-fission-born quintet state: Sublevel selections and trapping by multiexciton thermodynamics.The Journal of Physical Chemistry Letters9, 5855–5861 (2018). URL https://doi.org/10.1021/acs.jpclett.8b02396

work page doi:10.1021/acs.jpclett.8b02396 2018

[49] [50]

S., Bhat, V

Thomas, A. S., Bhat, V. N. & Tiwari, V. Rapid scan white light two-dimensional electronic spectroscopy with 100 kHz shot-to-shot detection.The Journal of Chemical Physics159, 244202 (2023). 42

2023

[50] [51]

N., Thomas, A

Bhat, V. N., Thomas, A. S., Bhattacharyya, A. & Tiwari, V. Rapid scan white light pump-probe spectroscopy with 100 kHz shot-to-shot detection.Opt. Continuum2, 1981–1995 (2023)

1981

[51] [52]

S.et al.Disordered light-harvesting aggregates can host functional vibronic couplings at room temperature.Nature Communications17, 3127 (2026)

Thomas, A. S.et al.Disordered light-harvesting aggregates can host functional vibronic couplings at room temperature.Nature Communications17, 3127 (2026). URL https://doi.org/10.1038/s41467-026-69815-0

work page doi:10.1038/s41467-026-69815-0 2026

[52] [53]

Marciniak, H.et al.Ultrafast exciton relaxation in microcrystalline pentacene films.Phys. Rev. Lett.99, 176402 (2007). URL https://link.aps.org/doi/10.1103/ PhysRevLett.99.176402

2007

[53] [54]

URL https://doi.org/10.1063/5.0312776

Patra, S.et al.Wavelength-dependent intramolecular singlet fission through an excimer-like intermediate.The Journal of Chemical Physics164, 054201 (2026). URL https://doi.org/10.1063/5.0312776

work page doi:10.1063/5.0312776 2026

[54] [55]

PMID: 31927968

Kim, J.et al.Non-born–oppenheimer molecular dynamics observed by coherent nuclear wave packets.The Journal of Physical Chemistry Letters11, 755–761 (2020). PMID: 31927968

2020

[55] [56]

Heo, W., Lee, C., Sohn, S. H. & Joo, T. Tracking nuclear wave packets in excited- state reactions via quantum mechanics/molecular dynamics simulations.The Journal of Chemical Physics162, 154108 (2025)

2025

[56] [57]

& Petelenz, P

Andrzejak, M., Sk´ ora, T. & Petelenz, P. Is Vibrational Coherence a Byproduct of Singlet Exciton Fission?The Journal of Physical Chemistry C123, 91–101 (2019). URL https://doi.org/10.1021/acs.jpcc.8b09124

work page doi:10.1021/acs.jpcc.8b09124 2019

[57] [58]

& Shukla, A

Sony, P. & Shukla, A. Large-scale correlated calculations of linear optical absorption and low-lying excited states of polyacenes: Pariser-parr-pople hamil- tonian.Phys. Rev. B75, 155208 (2007). URL https://link.aps.org/doi/10.1103/ 43 PhysRevB.75.155208

2007

[58] [59]

D., Haber, J

Folie, B. D., Haber, J. B., Refaely-Abramson, S., Neaton, J. B. & Ginsberg, N. S. Long-lived correlated triplet pairs in a pi-stacked crystalline pentacene derivative.Journal of the American Chemical Society140, 2326–2335 (2018). URL https://doi.org/10.1021/jacs.7b12662. PMID: 29392936

work page doi:10.1021/jacs.7b12662 2018

[59] [60]

K.et al.Morphology effectively controls singlet-triplet exciton relaxation and charge transport in organic semiconductors.Phys

Thorsmølle, V. K.et al.Morphology effectively controls singlet-triplet exciton relaxation and charge transport in organic semiconductors.Phys. Rev. Lett.102, 017401 (2009). URL https://link.aps.org/doi/10.1103/PhysRevLett.102.017401

work page doi:10.1103/physrevlett.102.017401 2009

[60] [61]

A., Smith, E

Farrow, D. A., Smith, E. R., Qian, W. & Jonas, D. M. The polarization anisotropy of vibrational quantum beats in resonant pump-probe experiments: Diagrammatic calculations for square symmetric molecules.Journal of Chemical Physics129, 174509 (2008)

2008

[61] [62]

Nature Chemistry16, 1680–1686 (2024)

Kim, J.et al.Coherent photoexcitation of entangled triplet pair states. Nature Chemistry16, 1680–1686 (2024). URL https://doi.org/10.1038/ s41557-024-01556-3

2024

[62] [63]

Chan Wai-Lun, L. M. & X-Y., Z. The energy barrier in singlet fission can be overcome through coherent coupling and entropic gain.Nature Chemistry4, 840 (2012). URL https://doi.org/10.1038/nchem.1436

work page doi:10.1038/nchem.1436 2012

[63] [64]

S., Nicholas R

Monahan, D. S., Nicholas R. & et al., Z. X.-Y. Dynamics of the triplet-pair state reveals the likely coexistence of coherent and incoherent singlet fission in crystalline hexacene.Nature Chemistry9, 341 (2017). URL https://doi.org/10. 1038/nchem.2665

2017

[64] [65]

URL https://doi.org/10.1021/jacs.7b02621

Breen, I.et al.Triplet separation drives singlet fission after femtosecond correlated triplet pair production in rubrene.Journal of the American Chemical Society 44 139, 11745–11751 (2017). URL https://doi.org/10.1021/jacs.7b02621. PMID: 28763611

work page doi:10.1021/jacs.7b02621 2017

[65] [66]

I., McCamey, D

Collins, M. I., McCamey, D. R. & Tayebjee, M. J. Y. Fluctuating exchange inter- actions enable quintet multiexciton formation in singlet fission.The Journal of Chemical Physics151, 164104 (2019). URL https://doi.org/10.1063/1.5115816

work page doi:10.1063/1.5115816 2019

[66] [67]

I., Campaioli, F., Tayebjee, M

Collins, M. I., Campaioli, F., Tayebjee, M. J. Y., Cole, J. H. & McCamey, D. R. Quintet formation, exchange fluctuations, and the role of stochastic resonance in singlet fission.Communications Physics6, 64 (2023). URL https://doi.org/10. 1038/s42005-023-01177-1

2023

[67] [68]

URL https://doi.org/10.1021/jacs.5c14936

He, G.et al.Bridge connectivity dictates spin interactions and triplet pair dynamics in intramolecular singlet fission.Journal of the American Chemi- cal Society148, 8136–8146 (2026). URL https://doi.org/10.1021/jacs.5c14936. PMID: 41700876

work page doi:10.1021/jacs.5c14936 2026

[68] [69]

The Journal of Chemical Physics , volume =

Jans´ ık, B., Høst, S., Kristensen, K. & Jørgensen, P. Local orbitals by minimizing powers of the orbital variance.The Journal of Chemical Physics134, 194104 (2011). URL https://doi.org/10.1063/1.3590361

work page doi:10.1063/1.3590361 2011

[69] [70]

& Jonas, D

Qian, W. & Jonas, D. M. Role of cyclic sets of transition dipoles in the pump– probe polarization anisotropy: Application to square symmetric molecules and perpendicular chromophore pairs.The Journal of Chemical Physics119, 1611– 1622 (2003)

2003

[70] [71]

S.et al.Unified model for singlet fission within a non-conjugated covalent pentacene dimer.Nature Communications8, 15171 (2017)

Basel, B. S.et al.Unified model for singlet fission within a non-conjugated covalent pentacene dimer.Nature Communications8, 15171 (2017)

2017

[71] [72]

D.et al.Exciton delocalization drives rapid singlet fission in nanopar- ticles of acene derivatives.Journal of the American Chemical Society137, 45 6790–6803 (2015)

Pensack, R. D.et al.Exciton delocalization drives rapid singlet fission in nanopar- ticles of acene derivatives.Journal of the American Chemical Society137, 45 6790–6803 (2015). URL https://doi.org/10.1021/ja512668r. PMID: 25946670

work page doi:10.1021/ja512668r 2015

[72] [73]

Millington, O.et al.The interplay of strongly and weakly exchange-coupled triplet pairs in intramolecular singlet fission.Journal of the American Chemical Society146, 29664–29674 (2024). 46

2024