Article
Chemistry, Physical
Paul L. Raston
Summary: Helium is the only solvent in which molecules can freely rotate, but the coupling between helium and molecules increases the moment of inertia. Infrared laser spectroscopy on molecules embedded in helium clusters can reveal rotationally resolved lines closely spaced than in vacuo. The coupling between helium and molecules is influenced by both mass and time, leading to asymmetry in the rovibrational lineshapes observed in the IR spectra.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Maria Rutigliano, Fernando Pirani
Summary: The scattering of CO molecules from a graphite surface was characterized using molecular dynamics simulations and a new reactive potential energy surface. Scattering events were found to occur through both single- and multi-bounces, with the initial vibrational state preserved. An intriguing stereodynamic effect was observed due to the heteronuclear character of the CO molecule, influencing the final rotational distributions of the scattered molecules.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Biochemistry & Molecular Biology
Massimiliano Bartolomei, Paul Martini, Ricardo Perez de Tudela, Tomas Gonzalez-Lezana, Marta I. Hernandez, Jose Campos-Martinez, Javier Hernandez-Rojas, Jose Breton, Paul Scheier
Summary: Ion yields of He N Ca+ obtained via high-resolution mass spectrometry generally decrease with N, with a more pronounced drop between N = 17 and N = 25, the computed quantum He N Ca+ evaporation energies resembling this behavior. The analysis of the energies and structures reveals that covering Ca+ with 17 He atoms leads to a cluster with one of the smallest energies per atom. As new atoms are added, they continue to fill the first shell at the expense of reducing its stability, until N = 25, which corresponds to the maximum number of atoms in that shell. Behavior of the evaporation energies and radial densities suggests liquid-like cluster structures.
Article
Chemistry, Physical
Man Ho Han, Dongjin Kim, Sangkuk Kim, Seung-Ho Yu, Da Hye Won, Byoung Koun Min, Keun Hwa Chae, Woong Hee Lee, Hyung-Suk Oh
Summary: This study demonstrates that nickel sulfide nanoparticles can mimic the electronic structure of nickel single atom catalysts and enhance catalytic activity in CO2 reduction reaction. However, the stability of nickel sulfide is low and needs further improvement.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Physical
Georges Sitja, Claude R. Henry
Summary: The study explores the activity of Pd-n (n = 1-5) clusters on nanostructured alumina films on a Ni3Al(111) surface, finding that single atoms become larger clusters at 533 K with activity proportional to the number of atoms in each cluster. The turnover frequency (TOF) per (surface-) atom remains constant at 533 K, similar to larger clusters and Pd(111) extended surfaces under the same experimental conditions.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Shijie Chai, Qixin Chen, Dongzheng Yang, Yanzi Zhou, Daiqian Xie
Summary: This work presents the quantum calculations of the spectral line shape parameters for (CO)-C-13 and (CO)-C-12 in the fundamental band, perturbed by He or Ar from 20 to 1000 K. The results show that the Dicke narrowing effect competes with the pressure broadening effect, and intermolecular inelastic collisions contribute significantly to the pressure broadening. The presence of the Dicke narrowing effect is essential for reproducing the spectral line profile and is in agreement with experimental observations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Yosuke Minowa, Shota Aoyagi, Sosuke Inui, Tomo Nakagawa, Gamu Asaka, Makoto Tsubota, Masaaki Ashida
Summary: Impurity injection into superfluid helium is a method with diverse applications, but the interaction mechanism with dense materials is still unclear. This study provides experimental evidence of the attraction between dense silicon nanoparticles and quantized vortex cores, and observes the phenomenon of quantized vortex reconnection.
Article
Chemistry, Physical
Zhongda Zeng, Enderalp Yakaboylu, Mikhail Lemeshko, Tao Shi, Richard Schmidt
Summary: The study proposes a coherent state ansatz to describe angulons, which are quasiparticles formed by a quantum rotor dressed by excitations of a many-body bath. The properties of angulons, such as energies, quasiparticle weights, and spectral functions, are revealed, and a persistent decrease in the impurity's rotational constant is observed due to many-body dressing. The study also discusses rotational spectroscopy and takes into account initial-state interactions, revealing their impact on the excitation spectrum.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Linxi Wang, Shyam Deo, Ahana Mukhopadhyay, Nicholas A. Pantelis, Michael J. Janik, Robert M. Rioux
Summary: Experimental kinetics demonstrate that catalytic lean CO oxidation over single Pd atoms exhibits a CO reaction order greater than unity, which is unique to Pd single atoms supported on CeO2 nanocubes. The ability of Pd atoms to access multiple formal oxidation states is the key factor in this emergent redox behavior. A microkinetic model and density functional theory calculations support the experimental findings and provide insights into the reaction mechanism.
Article
Astronomy & Astrophysics
Kirill Tuchin
Summary: This study investigates the effects of Lorentz and centrifugal forces on heavy hadrons traversing Quark-Gluon Plasma, finding that the probability of hadron dissociation is significantly influenced by electric and magnetic components, with greater dissociation probability for negatively charged heavy hadrons compared to positively charged ones in relativistic heavy-ion collisions.
Article
Materials Science, Multidisciplinary
Y. Q. Hu, P. Huang, F. Wang
Summary: The storage capacity of helium atoms in nanopore graphene/tungsten composites was investigated in this study. Molecular dynamics simulation results showed that helium atoms could be effectively absorbed in the nanopore, which can relieve stress concentration and delay the formation of large-sized helium bubbles, thus mitigating irradiation embrittlement.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Monica Canales, Juan Manuel Ramirez-de-Arellano, Juan Salvador Arellano, Luis Fernando Magana
Summary: The study found that the interaction between a semifullerene C-30 and a defected graphene layer leads to the adsorption of metal-doped C-30 at the bottom with different molecules, depending on the shape and dopant metal.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Physical
Wenhao Ren, Wenchao Ma, Xile Hu
Summary: Electrochemical CO reduction can be used to efficiently convert CO2 to chemical fuels. However, current membrane electrode assembly (MEA) CO electrolyzers suffer from low energy efficiency. This study shows that the transport of water and hydroxide ions at the quasi-two-phase interface of the cathode limits the performance of MEA electrolyzers at high current densities. By improving interfacial mass transport, the researchers achieved a lower cell voltage, higher stability, and higher Faradaic yield.
Article
Optics
Hui Jiang, Feng He
Summary: This study investigates the mechanisms of nonsequential triple ionization of Ar in strong laser fields, revealing the possibility of connecting three electrons step by step through tunneling effects to form a cascade rescattering channel.
Article
Multidisciplinary Sciences
Ulrich Bangert, Frank Stienkemeier, Lukas Bruder
Summary: Understanding the interaction between isolated chromophores and nanoparticles is a challenging task in nanoscience. This study provides insights into the interaction of base-free phthalocyanine molecules with He and Ne nanoclusters using high-resolution two-dimensional spectroscopy. The findings offer a promising approach for high-resolution molecular two-dimensional spectroscopy.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Atomic, Molecular & Chemical
Oliver Zingsheim, Holger S. P. Mueller, Luis Bonah, Frank Lewen, Sven Thorwirth, Stephan Schlemmer
Summary: A detailed analysis of the (sub-)millimeter-wave spectra of gauche-propanal is presented, focusing on the vibrational ground state and the lowest excited vibrational state. The study successfully assigns weak c-type transitions between tunneling states and takes into account the Coriolis interaction and Fermi resonance. The fundamental vibrational frequency of gauche-propanal is redetermined.
JOURNAL OF MOLECULAR SPECTROSCOPY
(2022)
Article
Astronomy & Astrophysics
O. Zingsheim, J. Massen, H. S. P. Mueller, B. Heyne, M. Fatima, L. Bonah, A. Belloche, F. Lewen, S. Schlemmer
Summary: This study aims to facilitate the astronomical detection of the Aa and Ag conformers of n-propanol by characterizing their rotational spectra. Through experimental and modeling research, we have successfully determined the rotational signatures of Aa and Ag n-propanol, offering possibilities for their astronomical detection.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Chemistry, Physical
Michael E. Harding, Filippo Lipparini, Juergen Gauss, Dieter Gerlich, Stephan Schlemmer, Ad van der Avoird
Summary: In this study, the vibration-rotation-tunneling (VRT) states of the He-H-3(+) complex were computed using an advanced electronic structure calculation. The results showed the existence of three global minima and five saddle points in the potential energy surface, as well as excited internal rotor states. The theoretical spectra generated from the calculations were in good agreement with the experimental spectra, confirming the accuracy of the computational results.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Maameyaa Asiamah, Paul L. Raston
Summary: The position of the symmetric CD3 stretching band in methanol and methanol-water clusters can serve as a useful indicator of their hydrogen-bonded cluster type. The findings are consistent with previous reports, confirming that methanol clusters from trimer to pentamer adopt a cyclic structure, and mixed clusters with one water molecule also exhibit cyclic behavior. Evidence is provided for the chair-like structure of the methanol trimer, cyclic behavior of mixed clusters with a larger number of water molecules, and the contribution of branched methanol clusters to signal depletion in larger clusters. Double-hybrid DFT calculations support these interpretations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Physics, Atomic, Molecular & Chemical
Holger S. P. Mueller, Jes K. Jorgensen, Jean-Claude Guillemin, Frank Lewen, Stephan Schlemmer
Summary: We prepared a doubly deuterated oxirane sample and studied its rotational spectrum in the laboratory. The spectroscopic parameters were determined accurately and used to tentatively identify c-CD2CH2O in the interstellar medium. The degree of deuteration in multiply deuterated isotopologs was found to be higher compared to singly deuterated variants.
JOURNAL OF MOLECULAR SPECTROSCOPY
(2023)
Article
Astronomy & Astrophysics
H. S. P. Mueller, R. T. Garrod, A. Belloche, V. M. Rivilla, K. M. Menten, I Jimenez-Serra, J. Martin-Pintado, F. Lewen, S. Schlemmer
Summary: Methylamine was the only alkylamine found in the interstellar medium until recently, with the addition of vinylamine and ethylamine, dimethylamine has become a target for space exploration. The rotational spectrum of dimethylamine has been studied up to 45 GHz until now, and this study expands the range to 76-1091 GHz. Non-detections of dimethylamine in certain regions suggest that it is less abundant than methylamine in those sources. Comparison with computational models indicates that the levels of dimethylamine in the models may be too high.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Instruments & Instrumentation
M. Hermanns, N. Wehres, B. Heyne, C. E. Honingh, U. U. Graf, S. Schlemmer
Summary: We present a home-built chirped-pulse Fourier transform millimeter wave (CP-FTMMW) spectrometer for high-resolution molecular spectroscopy. The experimental setup, including the chirp excitation source, optical beam path, and receiver, is described in detail. The performance of the CP-FTMMW instrument is characterized by recording spectra of methyl cyanide, hydrogen cyanide (HCN), and hydrogen isocyanide (HNC) products. The CP-FTMMW spectrometer exhibits significant signal enhancement and noise reduction compared to the emission spectrometer.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Chemistry, Multidisciplinary
Iren Simko, Christoph Schran, Fabien Brieuc, Csaba Fabri, Oskar Asvany, Stephan Schlemmer, Dominik Marx, Attila G. Csaszar
Summary: This work discusses the emergence of quantum nuclear delocalization and its rovibrational fingerprints in the van der Waals complex HHe3+. The results reveal that during the vibrations of the molecule, the solvating He is not restricted to be in a certain plane, but freely orbits the central proton, forming a three-dimensional torus.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Optics
Jianbao Zhao, Brant E. Billinghurst, Paul L. Raston
Summary: The far-infrared spectrum of room temperature formic acid labeled with 13C has been recorded and analyzed, leading to the determination of accurate line positions and predictions relevant to Earth's atmosphere and interstellar sources.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2024)
Article
Chemistry, Physical
Stephan Schlemmer, Eline Plaar, Divita Gupta, Weslley G. D. P. Silva, Thomas Salomon, Oskar Asvany
Summary: The antisymmetric C-H stretching vibration v(3) ((2)? ? (2)?) of ionised acetylene, C2H2+, has been studied again using a cryogenic 22-pole ion trap machine. Two action spectroscopic techniques, the novel leak-out spectroscopy (LOS) method and the more established laser-induced reactions (LIR) method, are applied and compared. By selecting specific masses and conducting experiments at cryogenic temperatures, uncontaminated spectra were obtained, allowing for a refinement of the spectroscopic parameters of this open-shell molecule.
Article
Chemistry, Physical
Holger S. P. Mueller, Atsuko Maeda, Frank Lewen, Stephan Schlemmer, Ivan R. Medvedev, Eric Herbst
Summary: An investigation of the rotational spectrum of the interstellar molecule thioformaldehyde revealed a multitude of absorption lines assignable to different vibrational states, providing important insights into the structure and properties of interstellar molecules.
Article
Chemistry, Physical
Oskar Asvany, Sven Thorwirth, Philipp C. C. Schmid, Thomas Salomon, Stephan Schlemmer
Summary: The ro-vibrational and pure rotational spectra of the linear ion HC3O+ were studied using a novel action spectroscopic technique named leak-out spectroscopy (LOS). A total of 45 ro-vibrational transitions within the fundamental band of the ν(1) C-H stretching mode were measured. Surprisingly, two hot bands were detected despite the cryogenic operation temperature. A new double-resonance rotational measurement scheme was established based on the LOS method. In addition, a pulsed laser system was employed to record a low resolution vibrational spectrum.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Divita Gupta, Weslley G. D. P. Silva, Jose L. Domenech, Eline Plaar, Sven Thorwirth, Stephan Schlemmer, Oskar Asvany
Summary: By applying a novel action spectroscopic technique in a 4 K cryogenic ion-trap instrument, the molecule c-C3H2D+ has been investigated using high-resolution rovibrational and pure rotational spectroscopy for the first time. A total of 126 rovibrational transitions within the fundamental band of the nu(1) symmetric C-H stretch were measured, which were used to predict pure rotational transition frequencies in the ground vibrational state. Based on these predictions, 16 rotational transitions between 90 and 230 GHz were observed using a double-resonance scheme. These measurements will enable the first radio-astronomical search for c-C3H2D+.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Physical
Maameyaa Asiamah, Paul L. Raston
Summary: The position of the symmetric CD3 stretching band provides insight into the hydrogen-bonded cluster type. Methanol clusters from trimer to pentamer are cyclic, as are mixed clusters with one water molecule. The methanol trimer adopts a chair-like structure and mixed clusters with more water molecules are also cyclic. Branched methanol clusters contribute to the depletion signal in larger methanol clusters, as supported by double-hybrid DFT calculations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Shreyak Banhatti, Daniel B. Rap, Aude Simon, Heloise Leboucher, Gabi Wenzel, Christine Joblin, Britta Redlich, Stephan Schlemmer, Sandra Bruenken
Summary: Polycyclic aromatic hydrocarbons (PAHs) are important components in astrophysical environments and are responsible for the aromatic infrared bands observed in galactic and extra-galactic spectra. PAHs can grow even at low temperatures and can be fragmented by UV photons, providing an alternative route for the formation of complex hydrocarbons in UV-rich interstellar regions. In this study, by analyzing the IR spectra of fragment ions formed from the dissociation of anthracene and phenanthrene molecules, the dominant structure of the fragment ion was identified to be the acenaphthylene cation. Molecular dynamics simulations further clarified the fragmentation process. These findings highlight the importance of species containing a pentagonal ring in the photochemistry of small PAHs.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
