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Schmahl S, Horn F, Jin J, Westphal H, Belder D, Asmis KR. Online-Monitoring of the Enantiomeric Ratio in Microfluidic Chip Reactors Using Chiral Selector Ion Vibrational Spectroscopy. Chemphyschem 2024; 25:e202300975. [PMID: 38418402 DOI: 10.1002/cphc.202300975] [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: 12/18/2023] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
A novel experimental approach for the rapid online monitoring of the enantiomeric ratio of chiral analytes in solution is presented. The charged analyte is transferred to the gas phase by electrospray. Diastereomeric complexes are formed with a volatile chiral selector in a buffer-gas-filled ion guide held at room temperature, mass-selected, and subsequently spectrally differentiated by cryogenic ion trap vibrational spectroscopy. Based on the spectra of the pure complexes in a small diastereomer-specific spectral range, the composition of diastereomeric mixtures is characterized using the cosine similarity score, from which the enantiomeric ratio in the solution is determined. The method is demonstrated for acidified alanine solutions and using three different chiral selectors (2-butanol, 1-phenylethanol, 1-amino-2-propanol). Among these, 2-butanol is the best choice as a selector for protonated alanine, also because the formation ratio of the corresponding diastereomeric complexes is found to be independent of the nature of the enantiomer. Subsequently, a microfluidic chip is implemented to mix enantiomerically pure alanine solutions continuously and determine the enantiomeric ratio online with minimal sample consumption within one minute and with competitive accuracy.
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Affiliation(s)
- Sonja Schmahl
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103, Leipzig, Germany
| | - Francine Horn
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103, Leipzig, Germany
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Jiaye Jin
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103, Leipzig, Germany
| | - Hannes Westphal
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103, Leipzig, Germany
| | - Detlev Belder
- Institut für Analytische Chemie, Universität Leipzig, Linnéstraße 3, 04103, Leipzig, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103, Leipzig, Germany
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2
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Silva WGDP, Bonah L, Schmid PC, Schlemmer S, Asvany O. Hyperfine-resolved rotational spectroscopy of HCNH. J Chem Phys 2024; 160:071101. [PMID: 38364002 DOI: 10.1063/5.0185365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/31/2024] [Indexed: 02/18/2024] Open
Abstract
The rotational spectrum of the molecular ion HCNH+ is revisited using double-resonance spectroscopy in an ion trap apparatus, with six transitions measured between 74 and 445 GHz. Due to the cryogenic temperature of the trap, the hyperfine splittings caused by the 14N quadrupolar nucleus were resolved for transitions up to J = 4 ← 3, allowing for a refinement of the spectroscopic parameters previously reported, especially the quadrupole coupling constant eQq.
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3
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Miyazaki M, Ono M, Otsuka R, Dopfer O, Fujii M. Electronic and vibrational spectroscopies of aromatic clusters with He in a supersonic jet: The case of neutral and cationic phenol-Hen (n = 1 and 2). J Chem Phys 2023; 159:134303. [PMID: 37787127 DOI: 10.1063/5.0169716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/15/2023] [Indexed: 10/04/2023] Open
Abstract
Van der Waals clusters composed of He and aromatic molecules provide fundamental information about intermolecular interactions in weakly bound systems. In this study, phenol-helium clusters (PhOH-Hen with n ≤ 2) are characterized for the first time by UV and IR spectroscopies. The S1 ← S0 origin and ionization energy both show small but additive shifts, suggesting π-bound structures of these clusters, a conclusion supported by rotational contour analyses of the S1 origin bands. The OH stretching vibrations of the PhOH moiety in the clusters match with those of bare PhOH in both the S0 and D0 states, illustrating the negligible perturbation of the He atoms on the molecular vibration. Matrix shifts induced by He attachment are discussed based on the observed band positions with the help of complementary quantum chemical calculations. For comparison, the UV and ionization spectra of PhOH-Ne are reported as well.
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Affiliation(s)
- Mitsuhiko Miyazaki
- Natural Science Division, Faculty of Core Research, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Megumi Ono
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Remina Otsuka
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, 10623 Berlin, Germany
- International Research Frontiers Initiative (IRFI), Institute of Innovation Research, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
| | - Masaaki Fujii
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
- International Research Frontiers Initiative (IRFI), Institute of Innovation Research, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
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4
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Gupta D, Silva WGDP, Doménech JL, Plaar E, Thorwirth S, Schlemmer S, Asvany O. High-resolution rovibrational and rotational spectroscopy of the singly deuterated cyclopropenyl cation, c-C 3H 2D . Faraday Discuss 2023; 245:298-308. [PMID: 37313855 PMCID: PMC10510037 DOI: 10.1039/d3fd00068k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 03/30/2023] [Indexed: 09/21/2023]
Abstract
Applying a novel action spectroscopic technique in a 4 K cryogenic ion-trap instrument, the molecule c-C3H2D+ has been investigated by high-resolution rovibrational and pure rotational spectroscopy for the first time. In total, 126 rovibrational transitions within the fundamental band of the ν1 symmetric C-H stretch were measured with a band origin centred at 3168.565 cm-1, which were used to predict pure rotational transition frequencies in the ground vibrational state. Based on these predictions, 16 rotational transitions were observed between 90 and 230 GHz by using a double-resonance scheme. These new measurements will enable the first radio-astronomical search for c-C3H2D+.
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Affiliation(s)
- Divita Gupta
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Weslley G D P Silva
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - José L Doménech
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
| | - Eline Plaar
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Sven Thorwirth
- 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.
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
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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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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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On-the-fly investigation of XUV excited large molecular ions using a high harmonic generation light source. Sci Rep 2022; 12:13191. [PMID: 35915132 PMCID: PMC9343369 DOI: 10.1038/s41598-022-17416-4] [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] [Received: 06/01/2022] [Accepted: 07/25/2022] [Indexed: 11/25/2022] Open
Abstract
We present experiments where extreme ultraviolet femtosecond light pulses are used to photoexcite large molecular ions at high internal energy. This is done by combining an electrospray ionization source and a mass spectrometer with a pulsed light source based on high harmonic generation. This allows one to study the interaction between high energy photons and mass selected ions in conditions that are accessible on large-scale facilities. We show that even without an ion trapping device, systems as large as a protein can be studied. We observe light induced dissociative ionization and proton migration in model systems such as reserpine, insulin and cytochrome c. These results offer new perspectives to perform time-resolved experiments with ultrashort pulses at the heart of the emerging field of attosecond chemistry.
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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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9
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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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10
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Buntine JT, Carrascosa E, Bull JN, Jacovella U, Cotter MI, Watkins P, Liu C, Scholz MS, Adamson BD, Marlton SJP, Bieske EJ. An ion mobility mass spectrometer coupled with a cryogenic ion trap for recording electronic spectra of charged, isomer-selected clusters. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043201. [PMID: 35489918 DOI: 10.1063/5.0085680] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Infrared and electronic spectra are indispensable for understanding the structural and energetic properties of charged molecules and clusters in the gas phase. However, the presence of isomers can potentially complicate the interpretation of spectra, even if the target molecules or clusters are mass-selected beforehand. Here, we describe an instrument for spectroscopically characterizing charged molecular clusters that have been selected according to both their isomeric form and their mass-to-charge ratio. Cluster ions generated by laser ablation of a solid sample are selected according to their collision cross sections with helium buffer gas using a drift tube ion mobility spectrometer and their mass-to-charge ratio using a quadrupole mass filter. The mobility- and mass-selected target ions are introduced into a cryogenically cooled, three-dimensional quadrupole ion trap where they are thermalized through inelastic collisions with an inert buffer gas (He or He/N2 mixture). Spectra of the molecular ions are obtained by tagging them with inert atoms or molecules (Ne and N2), which are dislodged following resonant excitation of an electronic transition, or by photodissociating the cluster itself following absorption of one or more photons. An electronic spectrum is generated by monitoring the charged photofragment yield as a function of wavelength. The capacity of the instrument is illustrated with the resonance-enhanced photodissociation action spectra of carbon clusters (Cn +) and polyacetylene cations (HC2nH+) that have been selected according to the mass-to-charge ratio and collision cross section with He buffer gas and of mass-selected Au2 + and Au2Ag+ clusters.
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Affiliation(s)
- Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - James N Bull
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Ugo Jacovella
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Mariah I Cotter
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Brian D Adamson
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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