1
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Dinu D, Ončák M, Thorwirth S, Liedl KR, Brünken S, Schlemmer S, Jusko P. Zero-Point-Energy Driven Isotopic Exchange of the [H 3O] - anion Probed by Mid-Infrared Action Spectroscopy. J Am Chem Soc 2024; 146:21634-21641. [PMID: 39049192 PMCID: PMC11311240 DOI: 10.1021/jacs.4c05543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/18/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024]
Abstract
We present the first observation of vibrational transitions in the [H3O]- anion, an intermediate in the anion-molecule reaction of water, H2O, and hydride, H-, using a laser-induced isotopic H/D exchange reaction action spectroscopy scheme applied to anions. The observed bands are assigned as the fundamental and first overtone of the H2O-H- vibrational stretching mode, based on anharmonic calculations within the vibrational perturbation theory and vibrational configuration interaction. Although the D2O·D- species has the lowest energy, our experiments confirm the D2O·H- isotope to be a sink of the H/D exchange reaction. Ab initio calculations corroborate that the formation of D2O·H- is favored, as the zero-point-energy difference is larger between D2 and H2 than between D2O·H- and D2O·D-.
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Affiliation(s)
- Dennis
F. Dinu
- Institute
of Materials Chemistry, TU Wien, Getreidemarkt 9/165, 1060 Vienna, Austria
- Department
of General, Inorganic and Theoretical Chemistry, Universität Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Milan Ončák
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Sven Thorwirth
- I.
Physikalisches Institut, Universität
zu Köln, Zülpicher Str. 77, 50937 Koln̈, Germany
| | - Klaus R. Liedl
- Department
of General, Inorganic and Theoretical Chemistry, Universität Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Sandra Brünken
- Radboud
University, FELIX Laboratory,
Institute for Molecules and Materials, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Stephan Schlemmer
- I.
Physikalisches Institut, Universität
zu Köln, Zülpicher Str. 77, 50937 Koln̈, Germany
| | - Pavol Jusko
- Max
Planck
Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748 Garching, Germany
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2
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Rap DB, Schrauwen JGM, Redlich B, Brünken S. Ionic fragmentation products of benzonitrile as important intermediates in the growth of polycyclic aromatic hydrocarbons. Phys Chem Chem Phys 2024; 26:7296-7307. [PMID: 38353151 PMCID: PMC10900304 DOI: 10.1039/d3cp05574d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
In various astronomical environments such as the interstellar medium or (exo)planetary atmospheres, an interplay of bottom-up growth and top-down destruction processes of (polycyclic) aromatic hydrocarbons (PAHs) takes place. To get more insight into the interplay of both processes, we disentangle the fragmentation and formation processes that take place upon dissociative ionization of benzonitrile. We build on previous spectroscopic detections of the ionic fragmentation products of benzonitrile and use these as reactants for low-temperature bottom-up ion-molecule reactions with acetylene. By combining kinetics and infrared action spectroscopy, we reveal exothermic pathways to various (polycyclic) aromatic molecules, including the pentalene and phenylacetylene radical cations. We determine the reaction rate coefficients and unambiguously assign the structures of the reaction products. The data is supplemented by potential energy surface calculations and the analysis of non-covalent interactions. This study shows the unexpected formation of a linked four- and six-membered ring structure (phenylcyclobutadiene radical cation) with molecular formula C10H8˙+, and not the commonly observed isomer naphthalene˙+. All observed reactions proceed via radiative association processes and are relevant for the chemistry in (cold) astrochemical environments.
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Affiliation(s)
- Daniël B Rap
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Johanna G M Schrauwen
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Britta Redlich
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Sandra Brünken
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
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3
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Thorwirth S, Steenbakkers K, Danowski T, Schmid PC, Bonah L, Asvany O, Brünken S, Schlemmer S. Gas-Phase Infrared Action Spectroscopy of CH 2Cl + and CH 3ClH +: Likely Protagonists in Chlorine Astrochemistry. Molecules 2024; 29:665. [PMID: 38338409 PMCID: PMC10856563 DOI: 10.3390/molecules29030665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/12/2024] Open
Abstract
Two fundamental halocarbon ions, CH2Cl+ and CH3ClH+, were studied in the gas phase using the FELion 22-pole ion trap apparatus and the Free Electron Laser for Infrared eXperiments (FELIX) at Radboud University, Nijmegen (the Netherlands). The vibrational bands of a total of four isotopologs, CH235,37Cl+ and CH335,37ClH+, were observed in selected wavenumber regions between 500 and 2900 cm-1 and then spectroscopically assigned based on the results of anharmonic force field calculations performed at the CCSD(T) level of theory. As the infrared photodissociation spectroscopy scheme employed probes singly Ne-tagged weakly bound complexes, complementary quantum-chemical calculations of selected species were also performed. The impact of tagging on the vibrational spectra of CH2Cl+ and CH3ClH+ is found to be virtually negligible for most bands; for CH3ClH+-Ne, the observations suggest a proton-bound structural arrangement. The experimental band positions as well as the best estimate rotational molecular parameters given in this work provide a solid basis for future spectroscopic studies at high spectral resolutions.
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Affiliation(s)
- Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
| | - Kim Steenbakkers
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands; (K.S.); (S.B.)
| | - Timon Danowski
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
| | - Philipp C. Schmid
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
| | - Luis Bonah
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
| | - Sandra Brünken
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands; (K.S.); (S.B.)
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln Zülpicher, Str. 77, 50937 Köln, Germany; (T.D.); (P.C.S.); (L.B.); (O.A.); (S.S.)
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4
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Steenbakkers K, van Boxtel T, Groenenboom GC, Asvany O, Redlich B, Schlemmer S, Brünken S. Leak-out spectroscopy as alternative method to rare-gas tagging for the Renner-Teller perturbed HCCH + and DCCD + ions. Phys Chem Chem Phys 2024; 26:2692-2703. [PMID: 38175663 PMCID: PMC10793980 DOI: 10.1039/d3cp04989b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/05/2023] [Indexed: 01/05/2024]
Abstract
Infrared messenger-tagging predissociation action spectroscopy (IRPD) is a well-established technique to record vibrational spectra of reactive molecular ions. One of its major drawbacks is that the spectrum of the messenger-ion complex is taken instead of that of the bare ion. In particular for small open-shell species, such as the Renner-Teller (RT) affected HCCH+ and DCCD+, the attachment of the tag may have a significant impact on the spectral features. Here we present the application of the novel leak-out spectroscopy (LOS) as a tag-free method to record the cis-bending of the HCCH+ (∼700 cm-1) and DCCD+ cations (∼520 cm-1), using a cryogenic ion trap end user station at the FELIX laboratory. We demonstrate that the obtained LOS spectrum is equivalent to a previously recorded laser-induced reactions (LIR) spectrum of HCCH+. The bending modes are the energetically lowest-lying vibrational modes targeted with LOS so far, showing its potential as a universal broadband spectroscopic technique. Furthermore, we have investigated the effect of the rare gas attachment by recording the vibrational spectra of Ne- and Ar-tagged HCCH+. We found that the Ne-attachment led to a shift in band positions and change in relative intensities, while the Ar-attachment even led to a complete quenching of the RT splitting, showing the importance of using a tag-free method for RT affected systems. The results are interpreted with the help of high-level ab initio calculations in combination with an effective Hamiltonian approach.
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Affiliation(s)
- Kim Steenbakkers
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Nijmegen, The Netherlands.
| | - Tom van Boxtel
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Nijmegen, The Netherlands.
| | - Gerrit C Groenenboom
- Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
| | - Britta Redlich
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Nijmegen, The Netherlands.
| | | | - Sandra Brünken
- Radboud University, FELIX Laboratory, Institute for Molecules and Materials, Nijmegen, The Netherlands.
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5
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Rap DB, Simon A, Steenbakkers K, Schrauwen JGM, Redlich B, Brünken S. Fingerprinting fragments of fragile interstellar molecules: dissociation chemistry of pyridine and benzonitrile revealed by infrared spectroscopy and theory. Faraday Discuss 2023; 245:221-244. [PMID: 37404008 PMCID: PMC10510038 DOI: 10.1039/d3fd00015j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/22/2023] [Indexed: 07/06/2023]
Abstract
The cationic fragmentation products in the dissociative ionization of pyridine and benzonitrile have been studied by infrared action spectroscopy in a cryogenic ion trap instrument at the Free-Electron Lasers for Infrared eXperiments (FELIX) Laboratory. A comparison of the experimental vibrational fingerprints of the dominant cationic fragments with those from quantum chemical calculations revealed a diversity of molecular fragment structures. The loss of HCN/HNC is shown to be the major fragmentation channel for both pyridine and benzonitrile. Using the determined structures of the cationic fragments, potential energy surfaces have been calculated to elucidate the nature of the neutral fragment partner. In the fragmentation chemistry of pyridine, multiple non-cyclic structures are formed, whereas the fragmentation of benzonitrile dominantly leads to the formation of cyclic structures. Among the fragments are linear cyano-(di)acetylene˙+, methylene-cyclopropene˙+ and o- and m-benzyne˙+ structures, the latter possible building blocks in interstellar polycyclic aromatic hydrocarbon (PAH) formation chemistry. Molecular dynamics simulations using density functional based tight binding (MD/DFTB) were performed and used to benchmark and elucidate the different fragmentation pathways based on the experimentally determined structures. The implications of the difference in fragments observed for pyridine and benzonitrile are discussed in an astrochemical context.
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Affiliation(s)
- Daniël B Rap
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Aude Simon
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Fédération FeRMI, CNRS & Université Toulouse III - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Kim Steenbakkers
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Johanna G M Schrauwen
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Britta Redlich
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
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6
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Dahlmann F, Dinu DF, Jusko P, Lochmann C, Gstir T, Marimuthu AN, Liedl KR, Brünken S, Wester R. Vibrational Predissociation Spectra of C 2 N - and C 3 N - : Bending and Stretching Vibrations. Chemphyschem 2023; 24:e202300262. [PMID: 37199236 PMCID: PMC10962567 DOI: 10.1002/cphc.202300262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/14/2023] [Accepted: 05/15/2023] [Indexed: 05/19/2023]
Abstract
We present infrared predissociation spectra of C2 N- (H2 ) and C 3 N- (H2 ) in the 300-1850 cm-1 range. Measurements were performed using the FELion cryogenic ion trap end user station at the Free Electron Lasers for Infrared eXperiments (FELIX) laboratory. For C2 N- (H2 ), we detected the CCN bending and CC-N stretching vibrations. For the C3 N- (H2 ) system, we detected the CCN bending, the CC-CN stretching, and multiple overtones and/or combination bands. The assignment and interpretation of the presented experimental spectra is validated by calculations of anharmonic spectra within the vibrational configuration interaction (VCI) approach, based on potential energy surfaces calculated at explicitly correlated coupled cluster theory (CCSD(T)-F12/cc-pVTZ-F12). The H2 tag acts as an innocent spectator, not significantly affecting the C2,3 N- bending and stretching mode positions. The recorded infrared predissociation spectra can thus be used as a proxy for the vibrational spectra of the bare anions.
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Affiliation(s)
- Franziska Dahlmann
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Dennis F. Dinu
- Department of GeneralInorganic and Theoretical ChemistryUniversität InnsbruckInnrain 80/826020InnsbruckAustria
| | - Pavol Jusko
- Max Planck Institute for Extraterrestrial PhysicsGießenbachstraße 185748GarchingGermany
| | - Christine Lochmann
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Thomas Gstir
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Aravindh N. Marimuthu
- Radboud UniversityInstitute for Molecules and MaterialsFELIX LaboratoryToernooiveld 76525EDNijmegen, theNetherlands
| | - Klaus R. Liedl
- Department of GeneralInorganic and Theoretical ChemistryUniversität InnsbruckInnrain 80/826020InnsbruckAustria
| | - Sandra Brünken
- Radboud UniversityInstitute for Molecules and MaterialsFELIX LaboratoryToernooiveld 76525EDNijmegen, theNetherlands
| | - Roland Wester
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
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7
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Steenbakkers K, Marimuthu AN, Redlich B, Groenenboom GC, Brünken S. A vibrational action spectroscopic study of the Renner-Teller- and spin-orbit-affected cyanoacetylene radical cation HC 3N . J Chem Phys 2023; 158:084305. [PMID: 36859081 DOI: 10.1063/5.0135000] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The linear radical cation of cyanoacetylene, HC3N+ (2Π), is not only of astrophysical interest, being the, so far undetected, cationic counterpart of the abundant cyanoaceteylene, but also of fundamental spectroscopic interest due to its strong spin-orbit and Renner-Teller interactions. Here, we present the first broadband vibrational action spectroscopic investigation of this ion through the infrared pre-dissociation (IRPD) method using a Ne tag. Experiments have been performed using the FELion cryogenic ion-trap instrument in combination with the FELIX free-electron lasers and a Laservision optical parametric oscillator/optical parametric amplifier system. The vibronic splitting patterns of the three interacting bending modes (ν5, ν6, ν7), ranging from 180 to 1600 cm-1, could be fully resolved revealing several bands that were previously unobserved. The associated Renner-Teller and intermode coupling constants have been determined by fitting an effective Hamiltonian to the experimental data, and the obtained spectroscopic constants are in reasonable agreement with previous photoelectron spectroscopy (PES) studies and ab initio calculations on the HC3N+ ion. The influence of the attached Ne atom on the infrared spectrum has been investigated by ab initio calculations at the RCCSD(T)-F12a level of theory, which strongly indicates that the discrepancies between the IRPD and PES data are a result of the effects of the Ne attachment.
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Affiliation(s)
- Kim Steenbakkers
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Aravindh N Marimuthu
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Britta Redlich
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Gerrit C Groenenboom
- Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Sandra Brünken
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
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8
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Kocheril GS, Gao HW, Wang LS. Vibrationally- and rotationally-resolved photoelectron imaging of cryogenically-cooled SbO 2–. Mol Phys 2023. [DOI: 10.1080/00268976.2023.2182610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Affiliation(s)
| | - Han-Wen Gao
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, RI, USA
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9
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Banhatti S, Rap DB, Simon A, Leboucher H, Wenzel G, Joblin C, Redlich B, Schlemmer S, Brünken S. Formation of the acenaphthylene cation as a common C 2H 2-loss fragment in dissociative ionization of the PAH isomers anthracene and phenanthrene. Phys Chem Chem Phys 2022; 24:27343-27354. [PMID: 36326610 PMCID: PMC9673687 DOI: 10.1039/d2cp03835h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/21/2022] [Indexed: 09/19/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are thought to be a major constituent of astrophysical environments, being the carriers of the ubiquitous aromatic infrared bands (AIBs) observed in the spectra of galactic and extra-galactic sources that are irradiated by ultraviolet (UV) photons. Small (2-cycles) PAHs were unambiguously detected in the TMC-1 dark cloud, showing that PAH growth pathways exist even at low temperatures. The processing of PAHs by UV photons also leads to their fragmentation, which has been recognized in recent years as an alternative route to the generally accepted bottom-up chemical pathways for the formation of complex hydrocarbons in UV-rich interstellar regions. Here we consider the C12H8+ ion that is formed in our experiments from the dissociative ionization of the anthracene and phenanthrene (C14H10) molecules. By employing the sensitive action spectroscopic scheme of infrared pre-dissociation (IRPD) in a cryogenic ion trap instrument coupled to the free-electron lasers at the FELIX Laboratory, we have recorded the broadband and narrow line-width gas-phase IR spectra of the fragment ions (C12H8+) and also the reference spectra of three low energy isomers of C12H8+. By comparing the experimental spectra to those obtained from quantum chemical calculations we have identified the dominant structure of the fragment ion formed in the dissociation process to be the acenaphthylene cation for both isomeric precursors. Ab initio molecular dynamics simulations are presented to elucidate the fragmentation process. This result reinforces the dominant role of species containing a pentagonal ring in the photochemistry of small PAHs.
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Affiliation(s)
- Shreyak Banhatti
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Daniël B Rap
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
| | - Aude Simon
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Fédération FeRMI, CNRS & Université Toulouse III - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Heloïse Leboucher
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Fédération FeRMI, CNRS & Université Toulouse III - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Gabi Wenzel
- Center for Interstellar Catalysis (InterCat), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie (IRAP), Université Toulouse III - Paul Sabatier, CNRS, CNES, 9 Avenue du Colonel Roche, 31028 Toulouse, France
| | - Britta Redlich
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
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10
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Schmid PC, Asvany O, Salomon T, Thorwirth S, Schlemmer S. Leak-Out Spectroscopy, A Universal Method of Action Spectroscopy in Cold Ion Traps. J Phys Chem A 2022; 126:8111-8117. [DOI: 10.1021/acs.jpca.2c05767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Philipp C. Schmid
- I. Physikalisches Institut der Universität zu Köln, Köln 50937, Germany
| | - Oskar Asvany
- I. Physikalisches Institut der Universität zu Köln, Köln 50937, Germany
| | - Thomas Salomon
- I. Physikalisches Institut der Universität zu Köln, Köln 50937, Germany
| | - Sven Thorwirth
- I. Physikalisches Institut der Universität zu Köln, Köln 50937, Germany
| | - Stephan Schlemmer
- I. Physikalisches Institut der Universität zu Köln, Köln 50937, Germany
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11
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Zeh D, Bast M, Martens J, Berden G, Oomens J, Brünken S, Schlemmer S, Schäfer M, Kuck D. Unidirectional Double- and Triple-Hydrogen Rearrangement Reactions Probed by Infrared Ion Spectroscopy. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1377-1392. [PMID: 35471836 DOI: 10.1021/jasms.2c00039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Unidirectional double-hydrogen (2H) and triple-hydrogen (3H) rearrangement reactions occur upon electron-ionization-induced fragmentation of trans-2-(4-N,N-dimethylaminobenzyl)-1-indanol (1), trans-2-(4-methoxybenzyl)-1-indanol (2), 4-(4-N,N-dimethylaminophenyl)-2-butanol (3), and related compounds, as reported some 35 years ago (Kuck, D.; Filges, U. Org. Mass Spectrom. 1988, 23, 643-653). These unusual intramolecular redox processes were found to dominate the mass spectra of long-lived, metastable ions. The present report provides independent evidence for the structures of the product ions formed by the 2H and 3H rearrangement in an ion trap instrument. The radical cations 1•+ and 3•+ as well as ionized 1-(4-N,N-dimethylaminophenyl)-5-(4-methoxyphenyl)-3-pentanol, 5•+, were generated by electrospray ionization from anhydrous acetonitrile solutions. The 2H and 3H fragment ions were obtained by collision-induced dissociation and characterized by IR ion spectroscopy and density functional theory calculations. Comparison of the experimental and calculated infrared ion spectra enabled the identification of the 2H rearrangement product ion, C9H14N+ (m/z 136), as an N,N-dimethyl-para-toluidinium ion bearing the extra proton ortho to the amino group, a tautomer which was calculated to be 31 kJ/mol less stable than the corresponding N-protonated form. The 3H rearrangement product ion, C8H13N•+ (m/z 123), formerly assumed to be a distonic ammonium ion bearing a cyclohexadienyl radical, was now identified as a conventional radical cation, ionized N,N-dimethyl-2,3-dihydro-para-toluidine. Thus, the 3H rearrangement represents an intramolecular transfer hydrogenation between a secondary alcohol and an ionized aromatic ring. Based on these structural assignments, more detailed mechanisms for the unidirectional 2H and 3H rearrangement reactions are proposed.
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Affiliation(s)
- Dennis Zeh
- Department of Chemistry, Institute of Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Köln, Germany
| | - Marcel Bast
- I. Physikalisches Institut, University of Cologne, Zülpicher Straße 77, 50937 Köln, Germany
| | - Jonathan Martens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Giel Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Jos Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Stephan Schlemmer
- I. Physikalisches Institut, University of Cologne, Zülpicher Straße 77, 50937 Köln, Germany
| | - Mathias Schäfer
- Department of Chemistry, Institute of Organic Chemistry, University of Cologne, Greinstraße 4, 50939 Köln, Germany
| | - Dietmar Kuck
- Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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12
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Dahlmann F, Jusko P, Lara-Moreno M, Halvick P, Marimuthu AN, Michaelsen T, Wild R, Geistlinger K, Schlemmer S, Stoecklin T, Wester R, Brünken S. Predissociation spectroscopy of cold CN −H 2 and CN −D 2. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2085204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Franziska Dahlmann
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Pavol Jusko
- Max Planck Institute for Extraterrestrial Physics, Garching, Germany
| | | | | | - Aravindh N. Marimuthu
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Nijmegen, the Netherlands
| | - Tim Michaelsen
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Robert Wild
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Katharina Geistlinger
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | | | | | - Roland Wester
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Sandra Brünken
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Nijmegen, the Netherlands
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13
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Rap DB, van Boxtel TJHH, Redlich B, Brünken S. Spectroscopic Detection of Cyano-Cyclopentadiene Ions as Dissociation Products upon Ionization of Aniline. J Phys Chem A 2022; 126:2989-2997. [PMID: 35512055 PMCID: PMC9125686 DOI: 10.1021/acs.jpca.2c01429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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The H-loss products
(C6H6N+) from
the dissociative ionization of aniline (C6H7N) have been studied by infrared predissociation spectroscopy in
a cryogenic ion trap instrument at the free electron laser for infrared
experiments (FELIX) laboratory. Broadband and narrow line width vibrational
spectra in the spectral fingerprint region of 550–1800 cm–1 have been recorded. The comparison to calculated
spectra of the potential isomeric structures of the fragment ions
reveals that the dominant fragments are five-membered cyano-cyclopentadiene
ions. Computed C6H7N•+ potential
energy surfaces suggest that the dissociation path leading to H loss
starts with an isomerization process, following a similar trajectory
as the one leading to HNC loss. The possible presence of cyano-cyclopentadiene
ions and related five-membered ring species in Titan’s atmosphere
and the interstellar medium are discussed.
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Affiliation(s)
- Daniël B Rap
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Tom J H H van Boxtel
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Britta Redlich
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Sandra Brünken
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
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14
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Müller D, Dopfer O. Microsolvation of H 2O +, H 3O +, and CH 3OH 2+ by He in a cryogenic ion trap: structure of solvation shells. Phys Chem Chem Phys 2022; 24:11222-11233. [PMID: 35481676 DOI: 10.1039/d2cp01192a] [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
Due to the weak interactions of He atoms with neutral molecules and ions, the preparation of size-selected clusters for the spectroscopic characterization of their structures, energies, and large amplitude motions is a challenging task. Herein, we generate H2O+Hen (n ≤ 9) and H3O+Hen (n ≤ 5) clusters by stepwise addition of He atoms to mass-selected ions stored in a cryogenic 22-pole ion trap held at 5 K. The population of the clusters as a function of n provides insight into the structure of the first He solvation shell around these ions given by the anisotropy of the cation-He interaction potential. To rationalize the observed cluster size distributions, the structural, energetic, and vibrational properties of the clusters are characterized by ab initio calculations up to the CCSD(T)/aug-cc-pVTZ level. The cluster growth around both the open-shell H2O+ and closed-shell H3O+ ions begins by forming nearly linear and equivalent OH⋯He hydrogen bonds (H-bonds) leading to symmetric structures. The strength of these H-bonds decreases slightly with n due to noncooperative three-body induction forces and is weaker for H3O+ than for H2O+ due to both enhanced charge delocalization and reduced acidity of the OH protons. After filling all available H-bonded sites, addition of further He ligands around H2O+ (n = 3-4) occurs at the electrophilic singly occupied 2pz orbital of O leading to O⋯He p-bonds stabilized by induction and small charge transfer from H2O+ to He. As this orbital is filled for H3O+, He atoms occupy in the n = 4-6 clusters positions between the H-bonded He atoms, leading to a slightly distorted regular hexagon ring for n = 6. Comparison between H3O+Hen and CH3OH2+Hen illustrates that CH3 substitution substantially reduces the acidity of the OH protons, so that only clusters up to n = 2 can be observed. The structure of the solvation sub-shells is visible in both the binding energies and the predicted vibrational OH stretch and bend frequencies.
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Affiliation(s)
- David Müller
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany.
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15
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Marimuthu AN, Steenbakkers K, Redlich B, Brünken S. The Zeeman effect in CO + observed with rotational action spectroscopy. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2067089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Aravindh N. Marimuthu
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Kim Steenbakkers
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Britta Redlich
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
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16
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Salomon T, Brackertz S, Asvany O, Savić I, Gerlich D, Harding ME, Lipparini F, Gauss J, van der Avoird A, Schlemmer S. The He–H3+ complex. II. Infrared predissociation spectrum and energy term diagram. J Chem Phys 2022; 156:144308. [DOI: 10.1063/5.0087427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The rotationally resolved infrared (IR) spectrum of the He–[Formula: see text] complex has been measured in a cryogenic ion trap experiment at a nominal temperature of 4 K. Predissociation of the stored complex has been invoked by excitation of the degenerate ν2 mode of the [Formula: see text] sub-unit using a pulsed optical parametric oscillator system. An assignment of the experimental spectrum became possible through one-to-one correlations with bands of the spectrum theoretically predicted in Paper I [Harding et al., J. Chem. Phys. 156, 144307 (2022)]. 19 bands have been assigned and analyzed, and the energy term diagram of the lower states of this floppy molecular complex has been derived from combination differences (CDs) in the experimental spectrum. Ground state combination differences (GSCDs) reveal a large part of the energy term diagram for the He–[Formula: see text] complex in its vibrational ground state, v = 0. Experimental and theoretical term energies agree within experimental accuracy for the rotational fine structure associated with the total angular momentum quantum number J and the parity e/ f as well as for the coarse spacing of the lowest K states of the complex. This favorable comparison shows that the potential energy surface (PES) calculated in Paper I is accurate. The barriers between the three equivalent global minima in this PES are relatively low and the He–[Formula: see text] complex is extremely floppy, with nearly unhindered internal rotation of the [Formula: see text] sub-unit. The resulting Coriolis interactions couple the internal and end-over-end rotation of the complex and contribute significantly to the energy terms. They are observed both in experiment and theory and are, e.g., the origin of different rotational constants for states of e and f parity. Also in this respect, experiment and theory agree very well. Despite the assignment and analysis of many bands of the extremely rich IR spectrum of He–[Formula: see text], higher levels of excitation, including the complex stretching mode, need further attention.
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Affiliation(s)
- Thomas Salomon
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
| | - Stefan Brackertz
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
| | - Igor Savić
- Department of Physics, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Dieter Gerlich
- Department of Physics, Technische Universität Chemnitz, D-09107 Chemnitz, Germany
| | - Michael E. Harding
- Institut für Nanotechnologie, Karlsruher Institut für Technologie (KIT), Campus Nord, Postfach 3640, D-76021 Karlsruhe, Germany
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, I-56124 Pisa, Italy
| | - Jürgen Gauss
- Department Chemie, Johannes Gutenberg-Universität Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Ad van der Avoird
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany
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17
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Dahlmann F, Lochmann C, Marimuthu AN, Lara-Moreno M, Stoecklin T, Halvick P, Raoult M, Dulieu O, Wild R, Schlemmer S, Brünken S, Wester R. Strong ortho/para effects in the vibrational spectrum of Cl -(H 2). J Chem Phys 2021; 155:241101. [PMID: 34972371 DOI: 10.1063/5.0073749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The predissociation spectrum of the Cl-35(H2) complex is measured between 450 and 800 cm-1 in a multipole radiofrequency ion trap at different temperatures using the FELIX infrared free electron laser. Above a certain temperature, the removal of the Cl-(p-H2) para nuclear spin isomer by ligand exchange to the Cl-(o-H2) ortho isomer is suppressed effectively, thereby making it possible to detect the spectrum of this more weakly bound complex. At trap temperatures of 30.5 and 41.5 K, we detect two vibrational bands of Cl-(p-H2) at 510(1) and 606(1) cm-1. Using accurate quantum calculations, these bands are assigned to transitions to the inter-monomer vibrational modes (v1,v2 l2 ) = (0, 20) and (1, 20), respectively.
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Affiliation(s)
- Franziska Dahlmann
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Christine Lochmann
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Aravindh N Marimuthu
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | | | | | - Philippe Halvick
- Université de Bordeaux, ISM, CNSR UMR 5255, 33405 Talence, France
| | - Maurice Raoult
- Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, 91405 Orsay, France
| | - Olivier Dulieu
- Université Paris-Saclay, CNRS, Laboratoire Aimé Cotton, 91405 Orsay, France
| | - Robert Wild
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - Sandra Brünken
- FELIX Laboratory, Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Roland Wester
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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18
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Asvany O, Schlemmer S. Rotational action spectroscopy of trapped molecular ions. Phys Chem Chem Phys 2021; 23:26602-26622. [PMID: 34817492 DOI: 10.1039/d1cp03975j] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rotational action spectroscopy is an experimental method in which rotational spectra of molecules, typically in the microwave to sub-mm-wave domain of the electromagnetic spectrum (∼1-1000 GHz), are recorded by action spectroscopy. Action spectroscopy means that the spectrum is recorded not by detecting the absorption of light by the molecules, but by the action of the light on the molecules, e.g., photon-induced dissociation of a chemical bond, a photon-triggered reaction, or photodetachment of an electron. Typically, such experiments are performed on molecular ions, which can be well controlled and mass-selected by guiding and storage techniques. Though coming with many advantages, the application of action schemes to rotational spectroscopy was hampered for a long time by the small energy content of a corresponding photon. Therefore, the first rotational action spectroscopic methods emerged only about one decade ago. Today, there exists a toolbox full of different rotational action spectroscopic schemes which are summarized in this review.
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Affiliation(s)
- Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
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19
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Panchagnula S, Bouwman J, Rap DB, Castellanos P, Candian A, Mackie C, Banhatti S, Brünken S, Linnartz H, Tielens AGGM. Structural investigation of doubly-dehydrogenated pyrene cations. Phys Chem Chem Phys 2020; 22:21651-21663. [PMID: 32729589 DOI: 10.1039/d0cp02272a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The vibrationally resolved spectra of the pyrene cation and doubly-dehydrogenated pyrene cation (C16H10˙+; Py+ and C16H8˙+; ddPy+) are presented. Infrared predissociation spectroscopy is employed to measure the vibrational spectrum of both species using a cryogenically cooled 22-pole ion trap. The spectrum of Py+ allows a detailed comparison with harmonic and anharmonic density functional theory (DFT) calculated normal mode frequencies. The spectrum of ddPy+ is dominated by absorption features from two isomers (4,5-ddPy+ and 1,2-ddPy+) with, at most, minor contributions from other isomers. These findings can be extended to explore the release of hydrogen from interstellar PAH species. Our results suggest that this process favours the loss of adjacent hydrogen atoms.
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Affiliation(s)
- Sanjana Panchagnula
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
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20
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High-resolution rovibrational spectroscopy of c- C3H2+: The ν7 C–H antisymmetric stretching band. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Thorwirth S, Harding ME, Asvany O, Brünken S, Jusko P, Lee KLK, Salomon T, McCarthy MC, Schlemmer S. Descendant of the X-ogen carrier and a ‘mass of 69’: infrared action spectroscopic detection of HC3O+ and HC3S+. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1776409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
| | - Michael E. Harding
- Institut für Physikalische Chemie, Abteilung für Theoretische Chemie, Karlsruher Institut für Technologie (KIT), Karlsruhe, Germany
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Pavol Jusko
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
| | | | - Thomas Salomon
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
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22
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Markus CR, Thorwirth S, Asvany O, Schlemmer S. High-resolution double resonance action spectroscopy in ion traps: vibrational and rotational fingerprints of CH 2NH 2. Phys Chem Chem Phys 2019; 21:26406-26412. [PMID: 31793941 DOI: 10.1039/c9cp05487a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By applying various action spectroscopic techniques in a 4 K cryogenic ion trap instrument, protonated methanimine, CH2NH2+, has been investigated by high-resolution rovibrational and pure rotational spectroscopy for the first time. In total, 39 rovibrational transitions within the fundamental band of the ν2 symmetric C-H stretch were measured around 3026 cm-1, which were used to predict pure rotational transition frequencies of CH2NH2+ in the ground vibrational state. Based on these predictions, nine rotational transitions were observed between 109 and 283 GHz using a novel double resonance method, which significantly improved the sensitivity of the rotational measurements. This double resonance method consists of rotational excitation followed by vibrational excitation, which is finally detected as a dip in the number of CH2NH2+-He complexes formed in the 4 K He bath of the trap. The new measurements and the derived predictions of pure rotational transitions will enable the first radio-astronomical search for CH2NH2+.
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Affiliation(s)
- Charles R Markus
- The University of Illinois Department of Chemistry, 600 S. Mathews Ave, Urbana, IL 61801, USA
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23
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Asvany O, Schlemmer S, Szidarovszky T, Császár AG. Infrared Signatures of the HHe n+ and DHe n+ ( n = 3-6) Complexes. J Phys Chem Lett 2019; 10:5325-5330. [PMID: 31430165 DOI: 10.1021/acs.jpclett.9b01911] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Combination of a cryogenic ion-trap machine, operated at 4.7 K, with the free-electron-laser FELIX allows the first experimental characterization of the unusually bright antisymmetric stretch (ν3) and π-bending (ν2) fundamentals of the He-X+-He (X = H, D) chromophore of the in situ prepared HHen+ and DHen+ (n = 3-6) complexes. The band origins obtained are fully supported by first-principles quantum-chemical computations, performed at the MP2, the CCSD(T), and occasionally the CCSDTQ levels employing extended basis sets. Both the experiments and the computations are consistent with structures for the species with n = 3 and 6 being of T-shaped C2v and of D4h symmetry, respectively, while the species with n = 4 are suggested to exhibit interesting dynamical phenomena related to large-amplitude motions.
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Affiliation(s)
- Oskar Asvany
- I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , 50937 Köln , Germany
| | - Stephan Schlemmer
- I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , 50937 Köln , Germany
| | - Tamás Szidarovszky
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry , ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group , Pázmány Péter sétány 1/A , H-1117 Budapest , Hungary
| | - Attila G Császár
- Laboratory of Molecular Structure and Dynamics, Institute of Chemistry , ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group , Pázmány Péter sétány 1/A , H-1117 Budapest , Hungary
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24
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Brünken S, Lipparini F, Stoffels A, Jusko P, Redlich B, Gauss J, Schlemmer S. Gas-Phase Vibrational Spectroscopy of the Hydrocarbon Cations l-C 3H +, HC 3H +, and c-C 3H 2+: Structures, Isomers, and the Influence of Ne-Tagging. J Phys Chem A 2019; 123:8053-8062. [PMID: 31422660 PMCID: PMC6755619 DOI: 10.1021/acs.jpca.9b06176] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
![]()
We
report the first gas-phase vibrational spectra of the hydrocarbon
ions C3H+ and C3H2+. The ions were produced by electron impact ionization of
allene. Vibrational spectra of the mass-selected ions tagged with
Ne were recorded using infrared predissociation spectroscopy in a
cryogenic ion trap instrument using the intense and widely tunable
radiation of a free electron laser. Comparison of high-level quantum
chemical calculations and resonant depletion measurements revealed
that the C3H+ ion is exclusively formed in its
most stable linear isomeric form, whereas two isomers were observed
for C3H2+. Bands of the energetically
favored cyclic c-C3H2+ are in excellent
agreement with calculated anharmonic frequencies, whereas for the
linear open-shell HCCCH+ (2Πg) a detailed theoretical description of the spectrum remains challenging
because of Renner–Teller and spin–orbit interactions.
Good agreement between theory and experiment, however, is observed
for the frequencies of the stretching modes for which an anharmonic
treatment was possible. In the case of linear l-C3H+, small but non-negligible effects of the attached Ne on the
ion fundamental band positions and the overall spectrum were found.
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Affiliation(s)
- Sandra Brünken
- FELIX Laboratory, Institute for Molecules and Materials , Radboud University , Toernooiveld 7c , NL-6525ED Nijmegen , The Netherlands.,I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , D-50937 Köln , Germany
| | - Filippo Lipparini
- Institut für Physikalische Chemie , Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14 , D-55128 Mainz , Germany.,Dipartimento di Chimica e Chimica Industriale , Università di Pisa , Via G. Moruzzi 13 , I-56124 Pisa , Italy
| | - Alexander Stoffels
- FELIX Laboratory, Institute for Molecules and Materials , Radboud University , Toernooiveld 7c , NL-6525ED Nijmegen , The Netherlands.,I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , D-50937 Köln , Germany
| | - Pavol Jusko
- I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , D-50937 Köln , Germany
| | - Britta Redlich
- FELIX Laboratory, Institute for Molecules and Materials , Radboud University , Toernooiveld 7c , NL-6525ED Nijmegen , The Netherlands
| | - Jürgen Gauss
- Institut für Physikalische Chemie , Johannes Gutenberg-Universität Mainz , Duesbergweg 10-14 , D-55128 Mainz , Germany
| | - Stephan Schlemmer
- I. Physikalisches Institut , Universität zu Köln , Zülpicher Str. 77 , D-50937 Köln , Germany
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