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Ueta H, Fukutani K. Rotational-Energy Transfer in H 2 Ortho-Para Conversion on a Metal Surface: Interplay between Electron and Phonon Systems. J Phys Chem Lett 2023; 14:7591-7596. [PMID: 37599301 DOI: 10.1021/acs.jpclett.3c01209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Clarifying energy transfer processes in molecular adsorption on solid surfaces is essential to understand the gas-surface interaction. Unlike the vibrational-energy transfer processes, which are thought to be well understood in detail, the rotational-energy transfer process still remains unclear. Considering the interconversion between ortho and para states of H2 is accompanied by the nuclear spin flip and the rotational-energy transfer, the surface-temperature dependence of the ortho-to-para conversion of molecularly chemisorbed H2 on Pd(210) is studied. The conversion rate is accelerated with an increase in surface temperature. Based on the conversion model proposed for metal surfaces, we analyze the temperature dependence of the conversion rate, taking into account both electron and phonon systems of the substrate. The rotational-energy transfer is most likely mediated by surface electrons with the assistance of the substrate phonons.
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Affiliation(s)
- Hirokazu Ueta
- Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
| | - Katsuyuki Fukutani
- Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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2
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Lau JA, Verma VB, Schwarzer D, Wodtke AM. Superconducting single-photon detectors in the mid-infrared for physical chemistry and spectroscopy. Chem Soc Rev 2023; 52:921-941. [PMID: 36649126 DOI: 10.1039/d1cs00434d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Applications of vibrational spectroscopy throughout the field of physical chemistry are limited by detectors with poor temporal resolution, low detection efficiency, and high background levels. Up to now, the field has relied upon detectors based on semiconducting materials with small bandgaps, which unavoidably leads to a compromise between good spectral response and noise at long wavelengths. However, a revolution in mid-infrared light detection is underway based on the interactions of photons with superconducting materials, which function under fundamentally different operating principles. Superconducting detectors were first used to detect light at shorter wavelengths. However, recent developments in their sensitivity toward mid-infrared wavelengths up to 10 μm provide new opportunities for applications in molecular science, such as infrared emission experiments, exoplanet spectroscopy and single molecule microscopy. In this tutorial review, we provide background information needed for the non-expert in superconducting light detection to apply these devices in the field of mid-infrared molecular spectroscopy. We present and compare the detection mechanisms and current developments of three types of superconducting detectors: superconducting nanowire single-photon detectors (SNSPDs), transition edge sensors (TESs), and microwave kinetic inductance detectors (MKIDs). We also highlight existing applications of SNSPDs for laser-induced infrared fluorescence experiments and discuss their potential for other molecular spectroscopy applications. Ultimately, superconducting infrared detectors have the potential to approach the sensitivity and characteristics of established single-photon detectors operating in the UV/Vis region, which have existed for almost a century and become an indispensable tool within the field of physical chemistry.
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Affiliation(s)
- Jascha A Lau
- Institute for Physical Chemistry, University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany.,Department of Dynamics at Surfaces, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Goettingen, Germany.
| | - Varun B Verma
- National Institute of Standards and Technology, Boulder, CO, USA
| | - Dirk Schwarzer
- Institute for Physical Chemistry, University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany.,Department of Dynamics at Surfaces, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Goettingen, Germany.
| | - Alec M Wodtke
- Institute for Physical Chemistry, University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany.,Department of Dynamics at Surfaces, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Goettingen, Germany. .,International Center for Advanced Studies of Energy Conversion, University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany
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DeVine JA, Choudhury A, Lau JA, Schwarzer D, Wodtke AM. Spin-Forbidden Carbon-Carbon Bond Formation in Vibrationally Excited α-CO. J Phys Chem A 2022; 126:2270-2277. [PMID: 35380441 PMCID: PMC9014413 DOI: 10.1021/acs.jpca.2c01168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Fourier transform
infrared spectroscopy of laser-irradiated cryogenic
crystals shows that vibrational excitation of CO leads to the production
of equal amounts of CO2 and C3O2.
The reaction mechanism is explored using electronic structure calculations,
demonstrating that the lowest-energy pathway involves a spin-forbidden
reaction of (CO)2 yielding C(3P) + CO2. C(3P) then undergoes barrierless recombination with
two other CO molecules forming C3O2. Calculated
intersystem crossing rates support the spin-forbidden mechanism, showing
subpicosecond spin-flipping time scales for a (CO)2 geometry
that is energetically consistent with states accessed through vibrational
energy pooling. This spin-flip occurs with an estimated ∼4%
efficiency; on the singlet surface, (CO)2 reconverts back
to CO monomers, releasing heat which induces CO desorption. The discovery
that vibrational excitation of condensed-phase CO leads to spin-forbidden
C–C bond formation may be important to the development of accurate
models of interstellar chemistry.
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Affiliation(s)
- Jessalyn A DeVine
- Abteilung für Dynamik an Oberflächen, Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, 37077 Göttingen, Germany
| | - Arnab Choudhury
- Abteilung für Dynamik an Oberflächen, Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, 37077 Göttingen, Germany.,Institute for Physical Chemistry, Georg-August Universität Göttingen, Tammannstaße 6, 37077 Göttingen, Germany
| | - Jascha A Lau
- Abteilung für Dynamik an Oberflächen, Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, 37077 Göttingen, Germany.,Institute for Physical Chemistry, Georg-August Universität Göttingen, Tammannstaße 6, 37077 Göttingen, Germany
| | - Dirk Schwarzer
- Abteilung für Dynamik an Oberflächen, Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, 37077 Göttingen, Germany
| | - Alec M Wodtke
- Abteilung für Dynamik an Oberflächen, Max-Planck-Institut für Multidisziplinäre Naturwissenschaften, Am Faßberg 11, 37077 Göttingen, Germany.,Institute for Physical Chemistry, Georg-August Universität Göttingen, Tammannstaße 6, 37077 Göttingen, Germany
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Condensed-phase isomerization through tunnelling gateways. Nature 2022; 612:691-695. [PMID: 36265512 PMCID: PMC9771804 DOI: 10.1038/s41586-022-05451-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 10/17/2022] [Indexed: 02/05/2023]
Abstract
Quantum mechanical tunnelling describes transmission of matter waves through a barrier with height larger than the energy of the wave1. Tunnelling becomes important when the de Broglie wavelength of the particle exceeds the barrier thickness; because wavelength increases with decreasing mass, lighter particles tunnel more efficiently than heavier ones. However, there exist examples in condensed-phase chemistry where increasing mass leads to increased tunnelling rates2. In contrast to the textbook approach, which considers transitions between continuum states, condensed-phase reactions involve transitions between bound states of reactants and products. Here this conceptual distinction is highlighted by experimental measurements of isotopologue-specific tunnelling rates for CO rotational isomerization at an NaCl surface3,4, showing nonmonotonic mass dependence. A quantum rate theory of isomerization is developed wherein transitions between sub-barrier reactant and product states occur through interaction with the environment. Tunnelling is fastest for specific pairs of states (gateways), the quantum mechanical details of which lead to enhanced cross-barrier coupling; the energies of these gateways arise nonsystematically, giving an erratic mass dependence. Gateways also accelerate ground-state isomerization, acting as leaky holes through the reaction barrier. This simple model provides a way to account for tunnelling in condensed-phase chemistry, and indicates that heavy-atom tunnelling may be more important than typically assumed.
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Lu D, Chen J, Guo H, Li J. Vibrational energy pooling via collisions between asymmetric stretching excited CO 2: a quasi-classical trajectory study on an accurate full-dimensional potential energy surface. Phys Chem Chem Phys 2021; 23:24165-24174. [PMID: 34671798 DOI: 10.1039/d1cp03687d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In low temperature plasmas, energy transfer between asymmetric stretching excited CO2 molecules can be highly efficient, which leads to further excitation (and de-excitation) of the CO2 molecules: CO2(vas) + CO2(vas) → CO2(vas + 1) + CO2(vas - 1). Through such a vibrational ladder climbing mechanism, CO2 can be activated and eventually dissociates. To gain mechanistic insight of such processes, a full-dimensional accurate potential energy surface (PES) for the CO2 + CO2 system is developed using the permutational invariant polynomial-neural network method based on CCSD(T)-F12a/AVTZ energies at about 39 000 geometries. This PES is used in quasi-classical trajectory (QCT) studies of the vibrational energy transfer between CO2 molecules excited in the asymmetric stretching mode. A machine learning algorithm is used to determine state-specific rate coefficients for the vibrational transfer processes from a limited data set. In addition to the CO2(vas + 1) + CO2(vas - 1) channel, the QCT simulations revealed significant contributions from the CO2(vas + 2,3) + CO2(vas - 2,3) channels, particularly at low collision energies/temperatures. These multi-vibrational-quantum processes are attributed to enhanced energy flow in the collisional complex formed by enhanced dipole-dipole interaction between asymmetric stretching excited CO2 molecules.
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Affiliation(s)
- Dandan Lu
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China. .,Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Jun Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA
| | - Jun Li
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China.
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Liu H, Fu S, Li X, Zhou J, Wang Y, Zhang X, Liu Y. Plasmon-driven light harvesting in poly(vinyl alcohol) films for precise surface topography modulation. OPTICS LETTERS 2021; 46:1828-1831. [PMID: 33857080 DOI: 10.1364/ol.422176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Efficient light harvesting is essential for advanced photonic devices. Complex micro/nano surface relief structures can be produced via light-triggered mechanical movement, but limited in organic active molecular units. In this Letter, we propose to embed noble-metal particles into light-inactive polyvinyl alcohol matrix to construct a light harvesting system driven by plasmon for inscription of surface relief gratings. Ultra-small-sized silver nuclei are generated in the polymer by pre-thermal treatment, acting as an accelerator for the subsequent photoinduced particle growth, hydrogen group cleavage, and matrix softening. Based on such properties, a complex plasmonic array carrying ultra-high-density information is achieved with peristrophic multiplexing holography. This Letter paves a bright way to realize data storage, information encryption, and optical microcavity.
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