Mechanically Interlocked Molecular Rotors on Pb(100)

Nano Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 13, 2025

The mechanical coupling between molecules represents a promising route for the development of molecular machines. Constructing gears requires easily rotatable and mutually interlocked pinions. Using scanning tunneling microscopy (STM), it is demonstrated that aluminum phthalocyanine (AlPc) on Pb(100) exhibit these properties. Unlike other phthalocyanines this substrate, isolated AlPc fluctuate two azimuthal orientations. Density functional theory (DFT) calculations confirm stable orientations single indicate relatively low rotation barrier. In STM-constructed dimers trimers, fluctuations diminish, various are stabilized. Induced collective all in trimers observed, demonstrating their interlocking. Potential functions describing angle distance dependencies intermolecular molecule–substrate interactions derived from DFT dimers; 52 experimentally determined trimer geometries reproduced using potentials. This intuitive approach may prove to be useful modeling larger structures beyond scope quantum descriptions.

Language: Английский

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Surface and interfacial sciences for future technologies

National Science Review, Journal Year: 2024, Volume and Issue: 11(9)

Published: Aug. 2, 2024

Physical science has undergone an evolutional transition in research focus from solid bulks to surfaces, culminating numerous prominent achievements. Currently, it is experiencing a new exploratory phase-interfacial science. Many technology with tremendous impact closely associated functional interface which delineates the boundary between disparate materials or phases, evokes complexities that surpass its pristine comprising and thereby unveils plethora of distinctive properties. Such may generate completely significantly enhanced These specific properties are related interfacial states formed at interfaces. Therefore, establishing quantitative relationship their functionalities become key scientific issue However, also faces several challenges such as invisibility characterization, inaccuracy calculation, difficulty precise construction. To tackle these challenges, people must develop strategies for detection, accurate computation, meticulous construction anticipated provide comprehensive toolbox tailored future explorations lay foundation technologies.

Language: Английский

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Hydrogen production in reverse Tesla valve reactor combining ethanol steam reforming and water gas shift reaction

Energy, Journal Year: 2025, Volume and Issue: unknown, P. 134783 - 134783

Published: Jan. 1, 2025

Language: Английский

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Machine Learning-Aided Prediction of Molecular Self-Assembly on Metal Surfaces

The Journal of Physical Chemistry C, Journal Year: 2025, Volume and Issue: 129(9), P. 4434 - 4442

Published: Feb. 24, 2025

The self-assembly of small organic molecules on metal surfaces presents a promising approach for fabricating numerous functional nanostructures. However, the diversity precursor and large-scale process pose challenge investigating molecular via scanning tunneling microscopy (STM) techniques density theory (DFT) calculations. We propose data-driven random forest classification (RFC) algorithm to predict behavior various surfaces. Taking nucleobases their derivatives as representatives, we have constructed data set consisting both experimental STM characterizations DFT RFC model is well-trained with 13 features shows desirable prediction determining arrangement identifying self-assembled structures. importance these in predicting targets are analyzed based model. To validate our model, three new that not involved training predicted Au Cu surfaces, which agrees well observations. Our strategy provides essential insights into understanding origin aids rational design targeted nanostructure.

Language: Английский

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Selective Adsorption and Crystalline Film Growth of Picene Molecules on the Pb(111) Surface

The Journal of Physical Chemistry C, Journal Year: 2025, Volume and Issue: 129(9), P. 4695 - 4700

Published: Feb. 26, 2025

The picene molecules grown on a Pb(111) substrate have been investigated by low-temperature scanning tunneling microscopy. Picene present selective adsorption at low coverage due to the quantum size effect of film. lattice exhibits chiral switching and rotation induced electric field. When increasing coverage, two crystalline phases, (110)-like (211̅) found in monolayer regime. Our results provide new choices ideas for preparing organic electronic devices.

Language: Английский

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Detection and Manipulation of Interaction Between Magnetic DyPc₂ Molecules and Superconducting Pb(111) Surface

Advanced Materials Interfaces, Journal Year: 2025, Volume and Issue: unknown

Published: March 3, 2025

Abstract Lanthanide double‐decker phthalocyanine (LnPc 2 ) complexes are highly coveted for their prospective uses in ultrahigh‐density data storage and quantum computing. Notably, the spin systems comprising these superconducting substrates exhibit unique magnetic interactions. Through scanning tunneling microscopy (STM) spectroscopy (STS) experiments, interaction between DyPc molecules Pb(111) substrate is investigated. Three distinct adsorption patterns of on experimentally observed. Combined with DFT calculations, it found that ligand normal self‐assembled monolayer (SAM) quenched, which attributed to strong charge transfer from Pb(111). However, special embedded SAM maintain due weak transfer, forming a complex system substrate. Similarly, located second layer same behavior. Under zero field, Yu–Shiba–Rusinov (YSR) resonances observed within energy gap both systems. The Kondo resonance pairing occur at similar scales, indicating coexistence competition. This ultimately results Kondo‐screened state. By controlling sample bias, molecule can be switched molecule.

Language: Английский

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Lignocellulose‐Derived Energy Materials and Chemicals: A Review on Synthesis Pathways and Machine Learning Applications

Small Methods, Journal Year: 2025, Volume and Issue: unknown

Published: April 23, 2025

Abstract Lignocellulose biomass, Earth's most abundant renewable resource, is crucial for sustainable production of high–value chemicals and bioengineered materials, especially energy storage. Efficient pretreatment vital to boost lignocellulose conversion bioenergy biomaterials, cut costs, broaden its energy–sector applications. Machine learning (ML) has become a key tool in this field, optimizing processes, improving decision‐making, driving innovation valorization This review explores main strategies – physical, chemical, physicochemical, biological, integrated methods evaluating their pros cons It also stresses ML's role refining these supported by case studies showing effectiveness. The examines challenges opportunities integrating ML into storage, underlining pretreatment's importance unlocking lignocellulose's full potential. By blending process knowledge with advanced computational techniques, work aims spur progress toward sustainable, circular bioeconomy, particularly storage solutions.

Language: Английский

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Adsorption-Site- and Orientation-Dependent Magnetism of a Molecular Switch on Pb(100)

ACS Nano, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 14, 2025

Tin phthalocyanine (SnPc) has been studied on superconducting Pb(100) using scanning tunneling microscopy and spectroscopy. Isolated molecules adsorb with their Sn ion below (SnPc↓) or above (SnPc↑) the molecular plane. These geometries lead to different adsorption sites, orientations, energies of frontier orbitals. A transition from SnPc↑ SnPc↓ can be induced by extracting electrons a single molecule. Density functional theory (DFT) calculations reproduce observed indicate that positive charge facilitates ↑–↓ transition. The orientations are essentially determined σ-orbitals peripheral N atoms exhibit minimum distances lone pairs nearest Pb substrate atoms. This binding scheme, which implies direct relationship between site orientation, is consistent many previous observations other substrates. In islands, forced onto less favorable sites. leads strong Yu–Shiba–Rusinov state at top sites revealing an spin. Similarly, spin hollow quenched conversion SnPc↓. calculated lowest unoccupied orbital these spin-state transitions.

Language: Английский

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Phase Separation of Binary Triptycenes by an Iodine Interlayer Film on a Ag(111) Surface

The Journal of Physical Chemistry Letters, Journal Year: 2025, Volume and Issue: unknown, P. 3034 - 3038

Published: March 17, 2025

We report the self-assembly behaviors of two triptycenes (Trip-1 and Trip-2) on metal surfaces without with an iodine passivation interlayer by combining scanning tunneling microscopy (STM) density functional theory (DFT) studies. On Ag(111) surface, Trip-1 molecules form islands through intermolecular aldehyde–aldehyde hydrogen bonding π–π stacking benzene rings. In contrast, Trip-2 lie flat dispersed surface. The introduction can break ordered assembly Trip-1. will be mixed in a disorderly manner. iodine-passivated long chains bonding. automatically separated, forming self-assembled binary monolayer. These results show that interface adjust mixture separation structurally analogous triptycenes.

Language: Английский

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Gating Single Molecules with Counterions

ACS Nano, Journal Year: 2025, Volume and Issue: unknown

Published: April 18, 2025

We report atomic-scale gating and visualization of local charge distribution within individual rare-earth-based molecular complexes on a metallic surface. The are formed by positively charged lanthanum ion coordinated to (pcam)3 molecule negatively counterion trapped underneath via electrostatic interactions Au(111) Local is performed adding an additional one side the complex, which results in redistribution charges complex positive shift frontier orbitals. This caused internal Stark effect induced added counterion. directly captured using tunneling spectroscopy spectroscopic mapping at 5 K substrate temperature. polarizability corroborated density functional theory analytical calculations based experimental findings. Furthermore, influence polarization nearby investigated cluster purposely assembled three complexes, reveals maintaining states as single complexes. These findings will enable design robust rare-earth be tailored for potential solid-state applications.

Language: Английский

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