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Sutton SF, Rotteger CH, Jarman CK, Tarakeshwar P, Sayres SG. Ultrafast Proton Transfer and Contact Ion-Pair Formation in Formic Acid Clusters. J Phys Chem Lett 2023; 14:8306-8311. [PMID: 37681673 DOI: 10.1021/acs.jpclett.3c01654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
The ultrafast proton transfer dynamics of homogeneous formic acid clusters (FA)n, n < 10, are investigated with femtosecond time-resolved mass spectrometry. We monitor the proton transfer pathway following Rydberg state electronic relaxation and find that successful ion pair formation increases logarithmically with cluster size. Ab initio calculations demonstrate similar excitation/relaxation behavior for each cluster, revealing a contact ion pair forms between two molecules composing the cluster before finally a formate anion (HCOO-) is dissociated by the probe pulse. The sub-ps time scale for rearrangement and proton transfer increases almost linearly with cluster size, requiring ∼67 fs per additional formic acid molecule and ranging from 213 ± 51 fs for the trimer to 667 ± 116 fs for FA9. The near-linear trends measured for both rearrangement lifetime and ion pair formation suggest that proton transfer is unlikely in the formic acid dimer but becomes prominent in small clusters.
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Affiliation(s)
- Shaun F Sutton
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Chase H Rotteger
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Carter K Jarman
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Scott G Sayres
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
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Imaging the photodissociation dynamics of MgO at 193 nm. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2112272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Macroscopic production of highly nuclear-spin-polarized molecules from IR-excitation and photodissociation of molecular beams. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.139092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Michael TJ, Ogden HM, Mullin AS. State-resolved rotational distributions and collision dynamics of CO molecules made in a tunable optical centrifuge. J Chem Phys 2021; 154:134307. [PMID: 33832253 DOI: 10.1063/5.0038372] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
State-resolved distributions and collision dynamics of optically centrifuged CO molecules with orientated angular momentum are investigated by probing the CO J = 29-80 rotational levels using high-resolution transient IR absorption spectroscopy. An optical centrifuge with tunable bandwidth is used to control the extent of rotational excitation in the sample. The rotational distributions are inverted with a maximum population in J = 62. Rotational levels with J > 62 have populations that correlate with the intensity profile of the optical trap. The full bandwidth trap excites CO up to the J = 80 level, while J = 67 is the highest level observed in the reduced bandwidth trap. Polarization-sensitive transient spectroscopy shows that the initial orientational anisotropy is r = 0.8 for levels with J ≥ 55, while anisotropy values are near r = 0.4 for levels with J < 50. The rotational distribution for J > 50 is broadened slightly by collisions, consistent with small |ΔJ| propensity rules for rotational energy transfer. Doppler-broadened line profiles show that the J = 60-80 levels have translational temperatures near Ttrans = 300 K and that these temperatures remain constant for as much as 24 gas kinetic collisions. Doppler linewidths for levels with J < 60 are broadened by non-resonant rotation-to-translation energy transfer. Kinetic analysis of transient signals shows that collisions with thermal bath molecules are the predominant relaxation pathway.
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Affiliation(s)
- Tara J Michael
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - Hannah M Ogden
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - Amy S Mullin
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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Lin K, Tso C, Kasai T. Beyond the rule of transition state: Identification of roaming routes in some cases of carbonyl compounds. J CHIN CHEM SOC-TAIP 2021. [DOI: 10.1002/jccs.202100039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- King‐Chuen Lin
- Department of Chemistry National Taiwan University Taipei Taiwan
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
| | - Cheng‐Jui Tso
- Department of Chemistry National Taiwan University Taipei Taiwan
| | - Toshio Kasai
- Department of Chemistry National Taiwan University Taipei Taiwan
- Institute of Scientific and Industrial Research Osaka University Osaka Japan
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Li FF, Ma YJ, Liu JX, Wang GJ, Wang FY. Photodissociation dynamics of AlO at 193 nm using time-sliced ion velocity imaging. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2007118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Fang-fang Li
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China
| | - Yu-jie Ma
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China
| | - Jia-xing Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China
| | - Guan-jun Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China
| | - Feng-yan Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200438, China
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Affiliation(s)
- Dong Yan
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
| | - Yu-jie Ma
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
| | - Fang-fang Li
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
| | - Jia-xing Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
| | - Guan-jun Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
| | - Feng-yan Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fudan University, Shanghai 200433, China
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Roaming Dynamics and Conformational Memory in Photolysis of Formic Acid at 193 nm Using Time-resolved Fourier-transform Infrared Emission Spectroscopy. Sci Rep 2020; 10:4769. [PMID: 32179782 PMCID: PMC7075954 DOI: 10.1038/s41598-020-61642-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 11/28/2019] [Indexed: 11/09/2022] Open
Abstract
In photodissociation of trans-formic acid (HCOOH) at 193 nm, we have observed two molecular channels of CO + H2O and CO2 + H2 by using 1 μs-resolved Fourier-transform infrared emission spectroscopy. With the aid of spectral simulation, the CO spectra are rotationally resolved for each vibrational state (v = 1-8). Each of the resulting vibrational and rotational population distributions is characteristic of two Boltzmann profiles with different temperatures, originating from either transition state pathway or OH-roaming to form the same CO + H2O products. The H2O roaming co-product is also spectrally simulated to understand the interplay with the CO product in the internal energy partitioning. Accordingly, this work has evaluated the internal energy disposal for the CO and H2O roaming products; especially the vibrational-state dependence of the roaming signature is reported for the first time. Further, given a 1 μs resolution, the temporal dependence of the CO/CO2 product ratio at v ≥ 1 rises from 3 to 10 of study, thereby characterizing the effect of conformational memory and well reconciling with the disputed results reported previously between absorption and emission methods.
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