0000000000347456

AUTHOR

Sandra Brünken

0000-0001-7175-4828

showing 4 related works from this author

Vibrational Excitation Hindering an Ion-Molecule Reaction: The c−C3H2+−H2 Collision Complex

2020

Experiments within a cryogenic 22-pole ion trap have revealed an interesting reaction dynamic phenomenon, where rovibrational excitation of an ionic molecule slows down a reaction with a neutral partner. This is demonstrated for the low-temperature hydrogen abstraction reaction $\mathrm{c}\text{\ensuremath{-}}{\mathrm{C}}_{3}{{\mathrm{H}}_{2}}^{+}+{\mathrm{H}}_{2}$, where excitation of the ion into the ${\ensuremath{\nu}}_{7}$ antisymmetric C-H stretching mode decreased the reaction rate coefficient toward the products $\mathrm{c}\text{\ensuremath{-}}{\mathrm{C}}_{3}{{\mathrm{H}}_{3}}^{+}+\mathrm{H}$. Supported by high-level quantum-chemical calculations, this observation is explained by th…

PhysicsGeneral Physics and AstronomyIonic bondingRotational–vibrational spectroscopyHydrogen atomHydrogen atom abstraction01 natural sciences7. Clean energyIonCrystallographyExcited stateProduct (mathematics)0103 physical sciencesMolecule010306 general physicsPhysical Review Letters
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Gas-phase detection of HSOD and empirical equilibrium structure of oxadisulfane

2006

We present the first gas phase spectra of singly deuterated oxadisulfane, HSOD, in its vibrational ground state. More than 100 transitions have been recorded with highest frequency accuracy using the Cologne Terahertz Spectrometer. The molecular parameters derived from a least squares fit analysis proof HSOD to be an almost accidental symmetric prolate top molecule with an asymmetry parameter kZK0.9985. Spectra of c-type and weaker b-type transitions have been recorded in the range from 716 to 772 GHz. The ratio of the dipole moments mc/mbZ2.4(3) has been derived from measured line intensities. The c-type transitions are split by the tunneling motion of a hindered internal rotation, whereas…

SpectrometerChemistrymedia_common.quotation_subjectOrganic ChemistryAnalytical chemistryAsymmetryMolecular physicsSpectral lineAnalytical ChemistryTerahertz spectroscopy and technologyInorganic ChemistryDipoleDeuteriumGround stateSpectroscopymedia_commonLine (formation)Journal of Molecular Structure
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Gas-Phase Vibrational Spectroscopy of the Hydrocarbon Cations l-C3H+, HC3H+, and c-C3H2+: Structures, Isomers, and the Influence of Ne-Tagging

2019

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…

FELIX Molecular Structure and Dynamics010304 chemical physicsInfraredAlleneAnharmonicityInfrared spectroscopyFELIX Infrared and Terahertz Spectroscopy010402 general chemistry01 natural sciencesMolecular physicsArticle0104 chemical sciencesIonchemistry.chemical_compoundchemistry0103 physical sciencesIon trapPhysical and Theoretical ChemistrySpectroscopyElectron ionization
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High-resolution rovibrational spectroscopy of c-C3H2+: The ν7 C–H antisymmetric stretching band

2020

Abstract The ν 7 antisymmetric C–H stretching fundamental of c- C 3 H 2 + has been characterized in a cryogenic 22-pole ion trap by a novel type of action spectroscopy, in which the rovibrational excitation of c- C 3 H 2 + is detected as a slowing down of the low-temperature reaction c- C 3 H 2 +  + H2 → C 3 H 3 + + H. Ninety-one rovibrational transitions with partly resolved fine structure doublets were measured in high resolution. Supported by high-level quantum chemical calculations, spectroscopic parameters were determined by fitting the observed lines with an effective Hamiltonian for an asymmetric rotor in a doublet electronic ground state, X ˜ A 1 2 , yielding a band origin at 3113.6…

010405 organic chemistryAntisymmetric relationChemistryOrganic ChemistryRotational–vibrational spectroscopy010402 general chemistry01 natural sciencesMolecular physics0104 chemical sciencesAnalytical ChemistryInorganic Chemistrysymbols.namesakesymbolsMoleculeIon trapGround stateHamiltonian (quantum mechanics)SpectroscopySpectroscopyExcitationJournal of Molecular Structure
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