1
|
Satterthwaite L, Koumarianou G, Carroll PB, Sedlik RJ, Wang I, McCarthy MC, Patterson D. Low-Temperature Gas-Phase Kinetics of Ethanol-Methanol Heterodimer Formation. J Phys Chem A 2023; 127:4096-4102. [PMID: 37119198 PMCID: PMC10184117 DOI: 10.1021/acs.jpca.3c01312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
The structures of gas-phase noncovalently bound clusters have long been studied in supersonic expansions. This method of study, while providing a wealth of information about the nature of noncovalent bonds, precludes observation of the formation of the cluster, as the clusters form just after the orifice of the pulsed valve. Here, we directly observe formation of ethanol-methanol dimers via microwave spectroscopy in a controlled cryogenic environment. Time profiles of the concentration of reagents in the cell yielded gas-phase reaction rate constants of kMe-g = (2.8 ± 1.4) × 10-13 cm3 molecule-1 s-1 and kMe-t = (1.6 ± 0.8) × 10-13 cm3 molecule-1 s-1 for the pseudo-second-order ethanol-methanol dimerization reaction at 8 K. The relaxation cross section between the gauche and trans conformers of ethanol was also measured using the same technique. In addition, thermodynamic relaxation between conformers of ethanol over time allowed for selection of conformer stoichiometry in the ethanol-methanol dimerization reaction, but no change in the ratio of dimer conformers was observed with changing ethanol monomer stoichiometry.
Collapse
Affiliation(s)
- Lincoln Satterthwaite
- Department of Chemistry and Biochemistry, Building 232, University of California, Santa Barbara, California 93106, United States
| | - Greta Koumarianou
- Department of Chemistry and Biochemistry, Building 232, University of California, Santa Barbara, California 93106, United States
| | - P Brandon Carroll
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, Massachusetts 02138, United States
| | - Robert J Sedlik
- Physics Department, Broida Hall, University of California, Santa Barbara, California 93106, United States
| | - Irene Wang
- Physics Department, Broida Hall, University of California, Santa Barbara, California 93106, United States
| | - Michael C McCarthy
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, Massachusetts 02138, United States
| | - David Patterson
- Physics Department, Broida Hall, University of California, Santa Barbara, California 93106, United States
| |
Collapse
|
2
|
Bunn HA, Schultz CP, Jernigan CM, Widicus Weaver SL. Laser-Induced Chemistry Observed during 248 nm Vacuum Ultraviolet Photolysis of an O 3 and CH 3NH 2 Mixture. J Phys Chem A 2020; 124:10838-10848. [PMID: 33307703 DOI: 10.1021/acs.jpca.0c09618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present an examination of the 248 nm VUV (vacuum ultraviolet) laser photolysis of an ozone (O3) and methylamine (CH3NH2) mixture as means to produce aminomethanol (NH2CH2OH). Aminomethanol is predicted to be the direct interstellar precursor to glycine and is therefore an important target for detection in the interstellar medium. However, due to its high reactivity under terrestrial conditions, aminomethanol evades gas-phase spectral detection. The insertion of O(1D) into methylamine is one proposed pathway to form aminomethanol. However, this formation pathway is highly exothermic and results in a complex mixture of reaction products, complicating spectral assignment. Additional reactions between methylamine and the other products of ozone photolysis lead to further complication of the chemistry. Here, we present a systematic experimental study of these reaction pathways. We have used direct absorption millimeter/submillimeter spectroscopy in a supersonic expansion to probe the reaction products, which include formaldehyde (H2CO), methanimine (CH2NH), formamide (HCONH2), and hydrogen cyanide (HCN) and absorption signals arising from at least two additional unknown products. In addition, we examine the effects of reaction time on the chemical formation pathways and discuss them in the context of O(1D) insertion chemistry with methylamine. We have built a kinetics box model to interpret the results that are observed. We then examine the implications of these results for future studies aimed at forming and detecting aminomethanol.
Collapse
Affiliation(s)
- Hayley A Bunn
- Department of Chemistry, Emory University, Atlanta, Georgia 30322-1007, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Chase P Schultz
- Department of Chemistry, Emory University, Atlanta, Georgia 30322-1007, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Christopher M Jernigan
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Susanna L Widicus Weaver
- Department of Chemistry, Emory University, Atlanta, Georgia 30322-1007, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| |
Collapse
|
3
|
Zou L, Motiyenko RA, Margulès L, Alekseev EA. Millimeter-wave emission spectrometer based on direct digital synthesis. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:063104. [PMID: 32611015 DOI: 10.1063/5.0004461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/31/2020] [Indexed: 06/11/2023]
Abstract
We present a millimeter-wave Fourier transform emission spectrometer whose design is based on the application of a direct digital synthesizer (DDS) up-converted into the Ku-band with subsequent frequency multiplication. The spectrometer covers the frequency range from 50 GHz to 110 GHz and from 150 GHz to 330 GHz. Owing to the fast frequency switching ability of the DDS in the spectrometer, the same radiation source is used both as a generator of short polarizing pulses and as a local oscillator for the heterodyne receiving system. Such a design provides intrinsically coherent reception that allows very long-term data averaging in the time domain, which improves considerably the maximum sensitivity of the spectrometer. The performances of the spectrometer including the data acquisition rate, the sensitivity, and the accuracy of line frequency measurements were tested on the rotational spectra of OCS, NH2CHO, and CH3CH2CN. We show that in the frequency range of 150-300 GHz, the maximum sensitivity of the spectrometer for a 10 min integration time is around 10-9 cm-1 (the minimal value of the absorption coefficient of detectable rotational transition) in the case of narrowband single frequency pulse excitation, and around 10-8 cm-1 in the case of broadband chirped-pulse excitation.
Collapse
Affiliation(s)
- Luyao Zou
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - Roman A Motiyenko
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - Laurent Margulès
- Université de Lille, Faculté des Sciences et Technologies, Département Physique, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, 59655 Villeneuve d'Ascq Cedex, France
| | - Eugen A Alekseev
- Institute of Radio Astronomy of the National Academy of Sciences of Ukraine (IRA NASU), 4, Mystetstv St., Kharkiv 61002, Ukraine
| |
Collapse
|
4
|
Trabelsi T, Francisco JS. Spectroscopic characterization of the first excited state and photochemistry of the HO 3 radical. J Chem Phys 2020; 152:064304. [PMID: 32061237 DOI: 10.1063/1.5134838] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the one-dimensional cuts of the six-dimensional potential energy surfaces (PESs) of the ground and lowest doublet and quartet electronic states of trans-HO3 at the MRCI-F12/aug-cc-pVTZ level of theory. Theoretical calculations predict that the first excited state (A2A) presents a real minimum on its PES and possesses a nonplanar structure. The adiabatic excitation energy at the MRCI+Q and MRCI-F12 levels shows that the A2A state lies in the near-infrared region. Both the transition dipole moment and the oscillator strength were predicted to be weak, which suggests that photodissociation of HO3 to produce OH and O2 after UV-Vis absorption is not a plausible mechanism. The harmonic vibrational frequencies and rotational constants of the weakly bound complex OH-O2 in the two electronic states were predicted to help in its detection. Our PES shows that the reactions of H + O3 or HO2 + O in their ground states do not lead to trans-HO3 in its ground electronic state if one of the component fragments, i.e., HO2(A2A') + O(3P) or H(2S) + O3(3B2), is excited.
Collapse
Affiliation(s)
- Tarek Trabelsi
- Department of Earth and Environment Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6243, USA
| | - Joseph S Francisco
- Department of Earth and Environment Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6243, USA
| |
Collapse
|
5
|
Bartlett MA, Kazez AH, Schaefer HF, Allen WD. Riddles of the structure and vibrational dynamics of HO 3 resolved near the ab initio limit. J Chem Phys 2019; 151:094304. [PMID: 31492062 DOI: 10.1063/1.5110291] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The hydridotrioxygen (HO3) radical has been investigated in many previous theoretical and experimental studies over several decades, originally because of its possible relevance to the tropospheric HOx cycle but more recently because of its fascinating chemical bonding, geometric structure, and vibrational dynamics. We have executed new, comprehensive research on this vexing molecule via focal point analyses (FPA) to approach the ab initio limit of optimized geometric structures, relative energies, complete quartic force fields, and the entire reaction path for cis-trans isomerization. High-order coupled cluster theory was applied through the CCSDT(Q) and even CCSDTQ(P) levels, and CBS extrapolations were performed using cc-pVXZ (X = 2-6) basis sets. The cis isomer proves to be higher than trans by 0.52 kcal mol-1, but this energetic ordering is achieved only after the CCSDT(Q) milestone is reached; the barrier for cis → trans isomerization is a minute 0.27 kcal mol-1. The FPA central re(O-O) bond length of trans-HO3 is astonishingly long (1.670 Å), consistent with the semiexperimental re distance we extracted from microwave rotational constants of 10 isotopologues using FPA vibration-rotation interaction constants (αi). The D0(HO-O2) dissociation energy converges to a mere 2.80 ± 0.25 kcal mol-1. Contrary to expectation for such a weakly bound system, vibrational perturbation theory performs remarkably well with the FPA anharmonic force fields, even for the torsional fundamental near 130 cm-1. Exact numerical procedures are applied to the potential energy function for the torsional reaction path to obtain energy levels, tunneling rates, and radiative lifetimes. The cis → trans isomerization occurs via tunneling with an inherent half-life of 1.4 × 10-11 s and 8.6 × 10-10 s for HO3 and DO3, respectively, thus resolving the mystery of why the cis species has not been observed in previous experiments executed in dissipative environments that allow collisional cooling of the trans-HO3 product. In contrast, the pure ground eigenstate of the cis species in a vacuum is predicted to have a spontaneous radiative lifetime of about 1 h and 5 days for HO3 and DO3, respectively.
Collapse
Affiliation(s)
- Marcus A Bartlett
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Arianna H Kazez
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Wesley D Allen
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| |
Collapse
|
6
|
Hu X, Zuo J, Xie C, Dawes R, Guo H, Xie D. Anab initiobased full-dimensional potential energy surface for OH + O2⇄ HO3and low-lying vibrational levels of HO3. Phys Chem Chem Phys 2019; 21:13766-13775. [DOI: 10.1039/c9cp02206f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A full-dimensional potential energy surface for HO3, including the HO + O2dissociation asymptote, is developed and rigorous quantum dynamics calculations based on this PES have been carried out to compute the vibrational energy levels of HO3.
Collapse
Affiliation(s)
- Xixi Hu
- Institute of Theoretical and Computational Chemistry
- Key Laboratory of Mesoscopic Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Junxiang Zuo
- Institute of Theoretical and Computational Chemistry
- Key Laboratory of Mesoscopic Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Changjian Xie
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque
- USA
| | - Richard Dawes
- Department of Chemistry
- Missouri University of Science and Technology
- Rolla
- USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque
- USA
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry
- Key Laboratory of Mesoscopic Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| |
Collapse
|
7
|
Lauzin C, Schmutz H, Agner JA, Merkt F. Chirped-pulse millimetre-wave spectrometer for the 140–180 GHz region. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1467055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- C. Lauzin
- Institute of condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Physical Chemistry Laboratory, ETH Zürich, Zürich, Switzerland
| | - H. Schmutz
- Physical Chemistry Laboratory, ETH Zürich, Zürich, Switzerland
| | - J. A. Agner
- Physical Chemistry Laboratory, ETH Zürich, Zürich, Switzerland
| | - F. Merkt
- Physical Chemistry Laboratory, ETH Zürich, Zürich, Switzerland
| |
Collapse
|
8
|
Roenitz KM, Hays BM, Powers CR, McCabe MN, Smith H, Widicus Weaver SL, Shipman ST. AC Stark Effect Observed in a Microwave-Millimeter/Submillimeter Wave Double-Resonance Experiment. J Phys Chem A 2018; 122:6321-6327. [PMID: 29993251 DOI: 10.1021/acs.jpca.8b02116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microwave-millimeter/submillimeter wave double-resonance spectroscopy has been developed with the use of technology typically employed in chirped pulse Fourier transform microwave spectroscopy and fast-sweep direct absorption (sub)millimeter-wave spectroscopy. This technique offers the high sensitivity provided by millimeter/submillimeter fast-sweep techniques with the rapid data acquisition offered by chirped pulse Fourier transform microwave spectrometers. Rather than detecting the movement of population as is observed in a traditional double-resonance experiment, instead we detected the splitting of spectral lines arising from the AC Stark effect. This new technique will prove invaluable when assigning complicated rotational spectra of complex molecules. The experimental design is presented along with the results from the double-resonance spectra of methanol as a proof-of-concept for this technique.
Collapse
Affiliation(s)
- Kevin M Roenitz
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Brian M Hays
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Carson R Powers
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Morgan N McCabe
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Houston Smith
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | | | - Steven T Shipman
- Division of Natural Sciences , New College of Florida , Sarasota , Florida 34243 , United States
| |
Collapse
|
9
|
A theoretical characterization of reactions of HOOO radical with guanine: formation of 8-oxoguanine. Struct Chem 2018. [DOI: 10.1007/s11224-018-1095-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
10
|
Fortenberry RC, Francisco JS, Lee TJ. Quantum Chemical Rovibrational Analysis of the HOSO Radical. J Phys Chem A 2017; 121:8108-8114. [DOI: 10.1021/acs.jpca.7b08121] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ryan C. Fortenberry
- Department of Chemistry & Biochemistry, Georgia Southern University, Statesboro, Georgia 30460, United States
| | - Joseph S. Francisco
- Department
of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Timothy J. Lee
- NASA Ames Research Center, MS 245-3 Moffett Field, California 94035-1000, United States
| |
Collapse
|
11
|
Licari D, Tasinato N, Spada L, Puzzarini C, Barone V. VMS-ROT: A New Module of the Virtual Multifrequency Spectrometer for Simulation, Interpretation, and Fitting of Rotational Spectra. J Chem Theory Comput 2017; 13:4382-4396. [PMID: 28742339 PMCID: PMC5636176 DOI: 10.1021/acs.jctc.7b00533] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Virtual Multifrequency Spectrometer (VMS) is a tool that aims at integrating a wide range of computational and experimental spectroscopic techniques with the final goal of disclosing the static and dynamic physical-chemical properties "hidden" in molecular spectra. VMS is composed of two parts, namely, VMS-Comp, which provides access to the latest developments in the field of computational spectroscopy, and VMS-Draw, which provides a powerful graphical user interface (GUI) for an intuitive interpretation of theoretical outcomes and a direct comparison to experiment. In the present work, we introduce VMS-ROT, a new module of VMS that has been specifically designed to deal with rotational spectroscopy. This module offers an integrated environment for the analysis of rotational spectra: from the assignment of spectral transitions to the refinement of spectroscopic parameters and the simulation of the spectrum. While bridging theoretical and experimental rotational spectroscopy, VMS-ROT is strongly integrated with quantum-chemical calculations, and it is composed of four independent, yet interacting units: (1) the computational engine for the calculation of the spectroscopic parameters that are employed as a starting point for guiding experiments and for the spectral interpretation, (2) the fitting-prediction engine for the refinement of the molecular parameters on the basis of the assigned transitions and the prediction of the rotational spectrum of the target molecule, (3) the GUI module that offers a powerful set of tools for a vis-à-vis comparison between experimental and simulated spectra, and (4) the new assignment tool for the assignment of experimental transitions in terms of quantum numbers upon comparison with the simulated ones. The implementation and the main features of VMS-ROT are presented, and the software is validated by means of selected test cases ranging from isolated molecules of different sizes to molecular complexes. VMS-ROT therefore offers an integrated environment for the analysis of the rotational spectra, with the innovative perspective of an intimate connection to quantum-chemical calculations that can be exploited at different levels of refinement, as an invaluable support and complement for experimental studies.
Collapse
Affiliation(s)
- Daniele Licari
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Nicola Tasinato
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - Lorenzo Spada
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy.,Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna , Via Selmi 2, I-40126 Bologna, Italy
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna , Via Selmi 2, I-40126 Bologna, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore , Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| |
Collapse
|
12
|
Barreau L, Martinez O, Crabtree KN, Womack CC, Stanton JF, McCarthy MC. Oxygen-18 Isotopic Studies of HOOO and DOOO. J Phys Chem A 2017; 121:6296-6303. [DOI: 10.1021/acs.jpca.7b05380] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Caroline C. Womack
- Department
of Chemistry, MIT, Cambridge, Massachusetts 02138, United States
| | - John F. Stanton
- Department of Chemistry & Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165, United States
| | | |
Collapse
|
13
|
Viana RB. On the structure of the simplest triselenide compound model and the stabilizing effect of water molecules. Polyhedron 2017. [DOI: 10.1016/j.poly.2017.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|