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Article ; Online: Competition between Water-Water Hydrogen Bonds and Water-π Bonds in Pyrene-Water Cluster Anions.

Salzmann, Heinrich / Rasmussen, Anne P / Eaves, Joel D / Weber, J Mathias

The journal of physical chemistry. A

2024 Volume 128, Issue 14, Page(s) 2772–2781

Abstract: We present infrared spectra and density functional theory calculations of hydrated pyrene anion clusters with up to four water molecules. The experimental spectra were acquired by using infrared Ar messenger photodissociation spectroscopy. Water ... ...

Abstract	We present infrared spectra and density functional theory calculations of hydrated pyrene anion clusters with up to four water molecules. The experimental spectra were acquired by using infrared Ar messenger photodissociation spectroscopy. Water molecules form clusters on the surface of the pyrene, forming hydrogen bonds with the π-system. The structures of the water clusters and their interaction with the π-system are encoded in OH stretching vibrational modes. We find that the interactions between water molecules are stronger than the interactions between water molecules and the π-system. While all clusters show multiple conformers, three- and four-membered rings are the lowest energy structures in the larger hydrates.
Language	English
Publishing date	2024-04-02
Publishing country	United States
Document type	Journal Article
ISSN	1520-5215
ISSN (online)	1520-5215
DOI	10.1021/acs.jpca.4c00997
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Water-Hydrocarbon Interactions in Anionic Pyrene Monohydrate.

LeMessurier, Natalie / Salzmann, Heinrich / Leversee, River / Weber, J Mathias / Eaves, Joel D

The journal of physical chemistry. B

2024 Volume 128, Issue 13, Page(s) 3200–3210

Abstract: Interactions between water and polycyclic aromatic hydrocarbons are essential in many aspects of chemistry, from interstellar and atmospheric processes to interfacial hydrophobicity and wetting phenomena. Despite their growing importance, the ... ...

Abstract	Interactions between water and polycyclic aromatic hydrocarbons are essential in many aspects of chemistry, from interstellar and atmospheric processes to interfacial hydrophobicity and wetting phenomena. Despite their growing importance, the intermolecular potentials of the water-hydrocarbon interactions are underdeveloped compared to the water-water potentials, and there are similarly few experimental probes that are sensitive to the details of the water-hydrocarbon potential. We present a combined experimental and computational study of anionic pyrene monohydrate, one of the simplest water/hydrocarbon clusters. The action spectrum in the OH region of the mass-selected cluster ion provides a rigorous benchmark for intermolecular potentials and computational methodologies. We identify missing intermolecular interactions and shortcomings in conventional dynamics calculations by comparing experimental data to density functional theory and classical molecular dynamics calculations. Kinetic trapping is prevalent, even for one water molecule and one pyrene molecule, leading to slow equilibration in conventional molecular dynamics calculations, even on nanosecond time scales and at low temperatures (50 K). At constant energy, temperature fluctuations for the pair of molecules are substantial. Immersing the system in a bath of soft spheres and employing parallel tempering alleviates kinetic trapping and dampens temperature fluctuations, bringing the system closer to the thermodynamic limit. With such augmented sampling, a simple, flexible water model reproduces the line width and the asymmetric broadening of the symmetric OH stretching mode, which we assign to spectral diffusion. In the OH stretching region, dynamics calculations predict a more intense antisymmetric peak than experiments observe but do not predict the bimodal split symmetric peak that the experiments show. Our work suggests that electronic polarization, missing in the empirical force field, is responsible for the first discrepancy and that quantum nuclear effects, captured neither in density functional theory nor in classical dynamics, may be responsible for the second.
Language	English
Publishing date	2024-03-25
Publishing country	United States
Document type	Journal Article
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.3c07777
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Article ; Online: Singlet fission for quantum information and quantum computing: the parallel JDE model.

Smyser, Kori E / Eaves, Joel D

Scientific reports

2020 Volume 10, Issue 1, Page(s) 18480

Abstract: Singlet fission is a photoconversion process that generates a doubly excited, maximally spin entangled pair state. This state has applications to quantum information and computing that are only beginning to be realized. In this article, we construct and ... ...

Abstract	Singlet fission is a photoconversion process that generates a doubly excited, maximally spin entangled pair state. This state has applications to quantum information and computing that are only beginning to be realized. In this article, we construct and analyze a spin-exciton hamiltonian to describe the dynamics of the two-triplet state. We find the selection rules that connect the doubly excited, spin-singlet state to the manifold of quintet states and comment on the mechanism and conditions for the transition into formally independent triplets. For adjacent dimers that are oriented and immobilized in an inert host, singlet fission can be strongly state-selective. We make predictions for electron paramagnetic resonance experiments and analyze experimental data from recent literature. Our results give conditions for which magnetic resonance pulses can drive transitions between optically polarized magnetic sublevels of the two-exciton states, making it possible to realize quantum gates at room temperature in these systems.
Language	English
Publishing date	2020-10-28
Publishing country	England
Document type	Journal Article
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/s41598-020-75459-x
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Article ; Online: Clock transitions guard against spin decoherence in singlet fission.

Lewis, Sina G / Smyser, Kori E / Eaves, Joel D

The Journal of chemical physics

2021 Volume 155, Issue 19, Page(s) 194109

Abstract: Short coherence times present a primary obstacle in quantum computing and sensing applications. In atomic systems, clock transitions (CTs), formed from avoided crossings in an applied Zeeman field, can substantially increase coherence times. We show how ... ...

Abstract	Short coherence times present a primary obstacle in quantum computing and sensing applications. In atomic systems, clock transitions (CTs), formed from avoided crossings in an applied Zeeman field, can substantially increase coherence times. We show how CTs can dampen intrinsic and extrinsic sources of quantum noise in molecules. Conical intersections between two periodic potentials form CTs in electron paramagnetic resonance experiments of the spin-polarized singlet fission photoproduct. We report on a pair of CTs for a two-chromophore molecule in terms of the Zeeman field strength, molecular orientation relative to the field, and molecular geometry.
Language	English
Publishing date	2021-11-21
Publishing country	United States
Document type	Journal Article
ZDB-ID	3113-6
ISSN	1089-7690 ; 0021-9606
ISSN (online)	1089-7690
ISSN	0021-9606
DOI	10.1063/5.0069344
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Article ; Online: Molecular Control of Triplet-Pair Spin Polarization and Its Optoelectronic Magnetic Resonance Probes.

Reid, Obadiah G / Johnson, Justin C / Eaves, Joel D / Damrauer, Niels H / Anthony, John E

Accounts of chemical research

2023 Volume 57, Issue 1, Page(s) 59–69

Abstract: ConspectusPreparing and manipulating pure magnetic states in molecular systems are the key initial requirements for harnessing the power of synthetic chemistry to drive practical quantum sensing and computing technologies. One route for achieving the ... ...

Abstract	ConspectusPreparing and manipulating pure magnetic states in molecular systems are the key initial requirements for harnessing the power of synthetic chemistry to drive practical quantum sensing and computing technologies. One route for achieving the requisite higher spin states in organic systems exploits the phenomenon of singlet fission, which produces pairs of triplet excited states from initially photoexcited singlets in molecular assemblies with multiple chromophores. The resulting spin states are characterized by total spin (quintet, triplet, or singlet) and its projection onto a specified molecular or magnetic field axis. These excited states are typically highly polarized but exhibit an impure spin population pattern. Herein, we report the prediction and experimental verification of molecular design rules that drive the population of a single pure magnetic state and describe the progress toward its experimental realization.A vital feature of this work is the close partnership among theory, chemical synthesis, and spectroscopy. We begin by presenting our theoretical framework for understanding spin manifold interconversion in singlet fission systems. This theory makes specific testable predictions about the intermolecular structure and orientation relative to an external magnetic field that should lead to pure magnetic state preparation and provides a powerful tool for interpreting magnetic spectra. We then test these predictions through detailed magnetic spectroscopy experiments on a series of new molecular architectures that meet one or more of the identified structural criteria. Many of these architectures rely on the synthesis of molecules with features unique to this effort: rigid bridges between chromophores in dimers, heteroacenes with tailored singlet/triplet-pair energy level matching, or side-group engineering to produce specific crystal structures. The spin evolution of these systems is revealed through our application and development of several magnetic resonance methods, each of which has different sensitivities and relevance in environments relevant to quantum applications.Our theoretical predictions prove to be remarkably consistent with our experimental results, though experimentally meeting all the structural prescriptions demanded by theory for true pure-state preparation remains a challenge. Our magnetic spectra agree with our model of triplet-pair behavior, including funneling of the population to the
Language	English
Publishing date	2023-12-16
Publishing country	United States
Document type	Journal Article
ZDB-ID	1483291-4
ISSN	1520-4898 ; 0001-4842
ISSN (online)	1520-4898
ISSN	0001-4842
DOI	10.1021/acs.accounts.3c00556
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Article ; Online: Entangled spin-polarized excitons from singlet fission in a rigid dimer.

Dill, Ryan D / Smyser, Kori E / Rugg, Brandon K / Damrauer, Niels H / Eaves, Joel D

Nature communications

2023 Volume 14, Issue 1, Page(s) 1180

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', ... ...

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.
Language	English
Publishing date	2023-03-02
Publishing country	England
Document type	Journal Article
ZDB-ID	2553671-0
ISSN	2041-1723 ; 2041-1723
ISSN (online)	2041-1723
ISSN	2041-1723
DOI	10.1038/s41467-023-36529-6
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Article: Surface-Trapped Hole Diffusion in CdS and CdSe: The Superexchange Mechanism

Cline, R. Peyton / Eaves, Joel D

Journal of physical chemistry. 2020 Dec. 15, v. 124, no. 51

2020

Abstract: In contrast to the conventional view that surface-trapped holes in CdS and CdSe nanoparticles are static and immobile, recent experimental and theoretical work has shown that these holes are dynamic and undergo diffusion along the surfaces of these ... ...

Abstract	In contrast to the conventional view that surface-trapped holes in CdS and CdSe nanoparticles are static and immobile, recent experimental and theoretical work has shown that these holes are dynamic and undergo diffusion along the surfaces of these particles. We present semiperiodic density functional theory calculations for nanocrystal surfaces of these materials and employ Green’s function methods to assess the mechanisms of trapped-hole diffusion. Bulk electronic states can serve as intermediate virtual states that link the donor and acceptor hole traps on the surface. The associated superexchange tunneling mechanism dominates over the conventional direct tunneling pathway. The methodology presented in this work is nonperturbative in nature and should be applicable to a wide range of other nanoscale problems in which underlying phenomena are strongly influenced by coupling to a dense manifold of electronic states.
Keywords	density functional theory ; nanocrystals ; physical chemistry
Language	English
Dates of publication	2020-1215
Size	p. 28244-28251.
Publishing place	American Chemical Society
Document type	Article
Note	NAL-AP-2-clean
ISSN	1932-7455
DOI	10.1021/acs.jpcc.0c07108
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Linear Response Theory for Water Transport Through Dry Nanopores.

Strong, Steven E / Eaves, Joel D

The journal of physical chemistry. A

2017 Volume 121, Issue 29, Page(s) 5377–5382

Abstract: Porous two-dimensional crystals like graphene have the potential to revolutionize reverse-osmosis membrane technology. The permeability is a common figure of merit that describes the ease with which water flows through a membrane. For two-dimensional ... ...

Abstract	Porous two-dimensional crystals like graphene have the potential to revolutionize reverse-osmosis membrane technology. The permeability is a common figure of merit that describes the ease with which water flows through a membrane. For two-dimensional crystals, the permeability can be orders of magnitude higher than it is in conventional reverse-osmosis membranes. We apply our Gaussian Dynamics nonequilibrium molecular dynamics simulation method to very hydrophobic two-dimensional membranes and find that the current-pressure drop relationship becomes nonlinear. In this regime, the conventional permeability is an inadequate descriptor of the passage process, and the transport mechanism becomes a two-step one. The backing pressure first causes the pore to wet, and after it reaches a threshold pressure, water transport takes place from the wet state. We recover a simple description of the transport process by applying linear response theory with respect to the wet reference state rather than the dry one. A macroscopic thermodynamic argument supports our mechanistic description and predicts the wetting threshold pressure as a function of the contact angle.
Language	English
Publishing date	2017-07-27
Publishing country	United States
Document type	Journal Article
ISSN	1520-5215
ISSN (online)	1520-5215
DOI	10.1021/acs.jpca.7b03192
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Article ; Online: Efficient photon upconversion enabled by strong coupling between silicon quantum dots and anthracene.

Wang, Kefu / Cline, R Peyton / Schwan, Joseph / Strain, Jacob M / Roberts, Sean T / Mangolini, Lorenzo / Eaves, Joel D / Tang, Ming Lee

Nature chemistry

2023 Volume 15, Issue 8, Page(s) 1172–1178

Abstract: Hybrid structures formed between organic molecules and inorganic quantum dots can accomplish unique photophysical transformations by taking advantage of their disparate properties. The electronic coupling between these materials is typically weak, ... ...

Abstract	Hybrid structures formed between organic molecules and inorganic quantum dots can accomplish unique photophysical transformations by taking advantage of their disparate properties. The electronic coupling between these materials is typically weak, leading photoexcited charge carriers to spatially localize to the dot or to a molecule at its surface. However, we show that by converting a chemical linker that covalently binds anthracene molecules to silicon quantum dots from a carbon-carbon single bond to a double bond, we access a strong coupling regime where excited carriers spatially delocalize across both anthracene and silicon. By pushing the system to delocalize, we design a photon upconversion system with a higher efficiency (17.2%) and lower threshold intensity (0.5 W cm
Language	English
Publishing date	2023-06-12
Publishing country	England
Document type	Journal Article
ZDB-ID	2464596-5
ISSN	1755-4349 ; 1755-4330
ISSN (online)	1755-4349
ISSN	1755-4330
DOI	10.1038/s41557-023-01225-x
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Article ; Online: The Dynamics of Water in Porous Two-Dimensional Crystals.

Strong, Steven E / Eaves, Joel D

The journal of physical chemistry. B

2017 Volume 121, Issue 1, Page(s) 189–207

Abstract: Porous two-dimensional crystals offer many promises for water desalination applications. For computer simulation to play a predictive role in this area, however, one needs to have reliable methods for simulating an atomistic system with hydrodynamic ... ...

Abstract	Porous two-dimensional crystals offer many promises for water desalination applications. For computer simulation to play a predictive role in this area, however, one needs to have reliable methods for simulating an atomistic system with hydrodynamic currents and interpretative tools to relate microscopic interactions to emergent macroscopic dynamical quantities, such as friction, slip length, and permeability. In this article, we use Gaussian dynamics, a nonequilibrium molecular dynamics method that provides microscopic insights into the interactions that control the flows of both simple liquids and liquid water through atomically small channels. In simulations of aqueous transport, we mimic the effect of changing the membrane chemical composition by adjusting the attractive strength of the van der Waals interactions between the membrane atoms and water. We find that the wetting contact angle, a common measure of a membrane's hydrophobicity, does not predict the permeability of a membrane. Instead, the hydrophobic effect is subtle, with both static and dynamic effects that can both help and hinder water transport through these materials. The competition between the static and dynamical hydrophobicity balances an atomic membrane's tendency to wet against hydrodynamic friction, and determines an optimal contact angle for water passage through nonpolar membranes. To a reasonable approximation, the optimal contact angle depends only on the aspect ratio of the pore. We also find that water molecules pass through the most hydrophobic membranes in a punctuated series of bursts that are separated by long pauses. A continuous-time Markov model of these data provides evidence of a molecular analogue to the clogging transition, a phenomenon observed in driven granular flows.
Language	English
Publishing date	2017-01-12
Publishing country	United States
Document type	Journal Article
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.6b09387
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