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Eaves JD. Multielectron Dynamics in the Condensed Phase: Quantum Structure-Function Relationships. Annu Rev Phys Chem 2024; 75:437-456. [PMID: 38941526 DOI: 10.1146/annurev-physchem-042018-052515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024]
Abstract
Quantum information promises dramatic advances in computing last seen in the digital revolution, but quantum hardware is fragile, noisy, and resource intensive. Chemistry has a role in developing new materials for quantum information that are robust to noise, scalable, and operable in ambient conditions. While molecular structure is the foundation for understanding mechanism and reactivity, molecular structure/quantum function relationships remain mostly undiscovered. Using singlet fission as a specific example of a multielectron process capable of producing long-lived spin-entangled electronic states at high temperatures, I describe how to exploit molecular structure and symmetry to gain quantum function and how some principles learned from singlet fission apply more broadly to quantum science.
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Affiliation(s)
- Joel D Eaves
- Department of Chemistry, University of Colorado, Boulder, Colorado, USA;
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2
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Greißel PM, Schroeder ZW, Thiel D, Ferguson MJ, Clark T, Guldi DM, Tykwinski RR. Controlling Interchromophore Coupling in Diamantane-Linked Pentacene Dimers To Create a "Binary" Pair. J Am Chem Soc 2024; 146:10875-10888. [PMID: 38579119 DOI: 10.1021/jacs.4c01507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Two isomeric pentacene dimers, each linked by a diamantane spacer, have been synthesized. These dimers are designed to provide experimental evidence to support quantum mechanical calculations, which predict the substitution pattern on the carbon-rich diethynyldiamantane spacer to be decisive in controlling the interpentacene coupling. Intramolecular singlet fission (i-SF) serves as a probe for the existence and strength of the electronic coupling between the two pentacenes, with transient absorption spectroscopy as the method of choice to characterize i-SF. 4,9-Substitution of diamantane provides a pentacene dimer (4,9-dimer) in which the two chromophores are completely decoupled and that, following photoexcitation, deactivates to the ground state analogous to a monomeric pentacene chromophore. Conversely, 1,6-substitution provides a pentacene dimer (1,6-dimer) that exhibits sufficiently strong coupling to drive i-SF, resulting in correlated triplet M(T1T1) yields close to unity and free triplet (T1 + T1) yields of ca. 50%. Thus, the diamantane spacer effectively switches "on" or "off" the coupling between the chromophores, based on the substitution pattern. The binary control of diamantane contrasts other known molecular spacers designed only to modulate the coupling strength between two pentacenes.
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Affiliation(s)
- Phillip M Greißel
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Zachary W Schroeder
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Dominik Thiel
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Michael J Ferguson
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Timothy Clark
- Computer Chemistry Center (CCC), Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nägelsbachstrasse 25, 91052 Erlangen, Germany
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Rik R Tykwinski
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
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Kim J, Teo HT, Hong Y, Cha H, Kim W, Chi C, Kim D. Elucidating Singlet-Fission-Born Multiexciton Dynamics via Molecular Engineering: A Dilution Principle Extended to Quintet Triplet Pair. J Am Chem Soc 2024; 146:10833-10846. [PMID: 38578848 DOI: 10.1021/jacs.4c01326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Multiexciton in singlet exciton fission represents a critical quantum state with significant implications for both solar cell applications and quantum information science. Two distinct fields of interest explore contrasting phenomena associated with the geminate triplet pair: one focusing on the persistence of long-lived correlation and the other emphasizing efficient decorrelation. Despite the pivotal nature of multiexciton processes, a comprehensive understanding of their dependence on the structural and spin properties of materials is currently lacking in experimental realizations. To address this gap in knowledge, molecular engineering was employed to modify the TIPS-tetracene structures, enabling an investigation of the structure-property relationships in spin-related multiexciton processes. In lieu of the time-resolved electron paramagnetic resonance technique, two time-resolved magneto-optical spectroscopies were implemented for quantitative analysis of spin-dependent multiexciton dynamics. The utilization of absorption and fluorescence signals as complementary optical readouts, in the presence of a magnetic field, provided crucial insights into geminate triplet pair dynamics. These insights encompassed the duration of multiexciton correlation and the involvement of the spin state in multiexciton decorrelation. Furthermore, simulations based on our kinetic models suggested a role for quintet dilution in multiexciton dynamics, surpassing the singlet dilution principle established by the Merrifield model. The integration of intricate model structures and time-resolved magneto-optical spectroscopies served to explicitly elucidate the interplay between structural and spin properties in multiexciton processes. This comprehensive approach not only contributes to the fundamental understanding of these processes but also aligns with and reinforces previous experimental studies of solid states and theoretical assessments.
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Affiliation(s)
- Juno Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Hao Ting Teo
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Yongseok Hong
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Hyojung Cha
- Department of Hydrogen and Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Chunyan Chi
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
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Dill RD, Joshi G, Thorley KJ, Anthony JE, Fluegel B, Johnson JC, Reid OG. Near-Infrared Absorption Features of Triplet-Pair States Assigned by Photoinduced-Absorption-Detected Magnetic Resonance. J Phys Chem Lett 2023; 14:2387-2394. [PMID: 36848633 PMCID: PMC10009807 DOI: 10.1021/acs.jpclett.2c03665] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/22/2023] [Indexed: 06/18/2023]
Abstract
Singlet fission proceeds through a manifold of triplet-pair states that are exceedingly difficult to distinguish spectroscopically. Here, we introduce a new implementation of photoinduced-absorption-detected magnetic resonance (PADMR) and use it to understand the excited-state absorption spectrum of a tri-2-pentylsilylethynyl pentadithiophene (TSPS-PDT) film. These experiments allow us to directly correlate magnetic transitions driven by RF with electronic transitions in the visible and near-infrared spectrum with high sensitivity. We find that the new near-infrared excited-state transitions that arise in thin films of TSPS-PDT are correlated with the magnetic transitions of T1, not 5TT. Thus, we assign these features to the excited-state absorption of 1TT, which is depleted when T1 states are driven to a spin configuration that forbids subsequent fusion. These results clarify the disputed origin of triplet-associated near-infrared absorption features in singlet-fission materials and demonstrate an incisive general purpose tool for studying the evolution of high-spin excited states.
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Affiliation(s)
- Ryan D. Dill
- University
of Colorado Boulder, Department of Chemistry, Boulder, Colorado 80309, United States
| | - Gajadhar Joshi
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Karl J. Thorley
- University
of Kentucky Center for Applied Energy Research, Lexington, Kentucky 40511, United States
| | - John E. Anthony
- University
of Kentucky Center for Applied Energy Research, Lexington, Kentucky 40511, United States
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Brian Fluegel
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Justin C. Johnson
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, University
of Colorado, Boulder, Colorado 80309, United States
| | - Obadiah G. Reid
- National
Renewable Energy Laboratory, Golden, Colorado 80401, United States
- Renewable
and Sustainable Energy Institute, University
of Colorado, Boulder, Colorado 80309, United States
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Dill RD, Smyser KE, Rugg BK, Damrauer NH, Eaves JD. Entangled spin-polarized excitons from singlet fission in a rigid dimer. Nat Commun 2023; 14:1180. [PMID: 36859382 PMCID: PMC9977721 DOI: 10.1038/s41467-023-36529-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 01/31/2023] [Indexed: 03/03/2023] Open
Abstract
Singlet fission, a process that splits a singlet exciton into a biexciton, has promise in quantum information. We report time-resolved electron paramagnetic resonance measurements on a conformationally well-defined acene dimer molecule, TIPS-BP1', designed to exhibit strongly state-selective relaxation to specific magnetic spin sublevels. The resulting optically pumped spin polarization is a nearly pure initial state from the ensemble. The long-lived spin coherences modulate the signal intrinsically, allowing a measurement scheme that substantially removes noise and uncertainty in the magnetic resonance spectra. A nonadiabatic transition theory with a minimal number of spectroscopic parameters allows the quantitative assignment and interpretation of the spectra. In this work, we show that the rigid dimer TIPS-BP1' supports persistent spin coherences at temperatures far higher than those used in conventional superconducting quantum hardware.
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Affiliation(s)
- Ryan D. Dill
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Kori E. Smyser
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Brandon K. Rugg
- grid.419357.d0000 0001 2199 3636National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401 USA
| | - Niels H. Damrauer
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA ,grid.266190.a0000000096214564Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309 USA
| | - Joel D. Eaves
- grid.266190.a0000000096214564Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309 USA ,grid.266190.a0000000096214564Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309 USA
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Campanella AJ, Üngör Ö, Zadrozny JM. Quantum Mimicry With Inorganic Chemistry. COMMENT INORG CHEM 2023; 44:11-53. [PMID: 38515928 PMCID: PMC10954259 DOI: 10.1080/02603594.2023.2173588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Quantum objects, such as atoms, spins, and subatomic particles, have important properties due to their unique physical properties that could be useful for many different applications, ranging from quantum information processing to magnetic resonance imaging. Molecular species also exhibit quantum properties, and these properties are fundamentally tunable by synthetic design, unlike ions isolated in a quadrupolar trap, for example. In this comment, we collect multiple, distinct, scientific efforts into an emergent field that is devoted to designing molecules that mimic the quantum properties of objects like trapped atoms or defects in solids. Mimicry is endemic in inorganic chemistry and featured heavily in the research interests of groups across the world. We describe a new field of using inorganic chemistry to design molecules that mimic the quantum properties (e.g. the lifetime of spin superpositions, or the resonant frequencies thereof) of other quantum objects, "quantum mimicry." In this comment, we describe the philosophical design strategies and recent exciting results from application of these strategies.
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Affiliation(s)
- Anthony J. Campanella
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
| | - Ökten Üngör
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
| | - Joseph M. Zadrozny
- Department of Chemistry, Colorado State University, Fort Collins, CO, USA, Address: 200 W. Lake St, Campus Delivery 1872, Fort Collins, CO 80523, USA
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Triplet-pair spin signatures from macroscopically aligned heteroacenes in an oriented single crystal. Proc Natl Acad Sci U S A 2022; 119:e2201879119. [PMID: 35858318 PMCID: PMC9303990 DOI: 10.1073/pnas.2201879119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The photo-driven process of singlet fission generates coupled triplet pairs (TT) with fundamentally intriguing and potentially useful properties. The quintet 5TT0 sublevel is particularly interesting for quantum information because it is highly entangled, is addressable with microwave pulses, and could be detected using optical techniques. Previous theoretical work on a model Hamiltonian and nonadiabatic transition theory, called the JDE model, has determined that this sublevel can be selectively populated if certain conditions are met. Among the most challenging, the molecules within the dimer undergoing singlet fission must have their principal magnetic axes parallel to one another and to an applied Zeeman field. Here, we present time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy of a single crystal sample of a tetracenethiophene compound featuring arrays of dimers aligned in this manner, which were mounted so that the orientation of the field relative to the molecular axes could be controlled. The observed spin sublevel populations in the paired TT and unpaired (T+T) triplets are consistent with predictions from the JDE model, including preferential 5TT0 formation at z ‖ B0, with one caveat-two 5TT spin sublevels have little to no population. This may be due to crossings between the 5TT and 3TT manifolds in the field range investigated by TR-EPR, consistent with the intertriplet exchange energy determined by monitoring photoluminescence at varying magnetic fields.
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