Project leaders: Schlemmer, Stephan (PH1); Thorwirth, Sven (PH1); Asvany, Oskar (PH1)
In this sub-project we want to record spectra of negative ions which are believed to play a role in the physics and chemistry of the interstellar medium. They are a sink for the electrons produced by cosmic ray ionisation and some anions have already been found in the ISM but their role in the chemical evolution of the ISM is not understood very well. For small species like deprotonated methanol, CH3O– , we aim for rotationally resolved vibrational spectra and pure rotational spectra with our unique action spectroscopy methods. Such anions should be present in the ISM based on the very high abundance of the parent molecule and it will therefore be possible to detect them in CRC based collaborations by their fingerprint rotational spectra. Likewise, infrared spectra of negatively charged medium sized hydrocarbons, in particular polycyclic aromatic hydrocarbons (PAHs), will be recorded to obtain a first account of the amount of negatively charged PAHs. A first prime target in this research will be the benzene anion (C6H6– ) and also deprotonated benzene (C6H5– ). Such a new step in ion spectroscopy is needed in the era of the JWST and ALMA telescopes which provide infrared and also far-infrared spectra in tremendous detail such that more anions will be found and their role can be investigated.
Publications
2024
Thorwirth, Sven; Steenbakkers, Kim; Danowski, Timon; Schmid, Philipp C.; Bonah, Luis; Asvany, Oskar; Brünken, Sandra; Schlemmer, Stephan
Gas-Phase Infrared Action Spectroscopy of CH2Cl+ and CH3ClH+: Likely Protagonists in Chlorine Astrochemistry Journal Article
In: Molecules, vol. 29, no. 3, 2024, ISSN: 1420-3049.
@article{Thorwirth2024,
title = {Gas-Phase Infrared Action Spectroscopy of CH2Cl^{+} and CH3ClH^{+}: Likely Protagonists in Chlorine Astrochemistry},
author = {Sven Thorwirth and Kim Steenbakkers and Timon Danowski and Philipp C. Schmid and Luis Bonah and Oskar Asvany and Sandra Brünken and Stephan Schlemmer},
doi = {10.3390/molecules29030665},
issn = {1420-3049},
year = {2024},
date = {2024-02-00},
urldate = {2024-02-00},
journal = {Molecules},
volume = {29},
number = {3},
publisher = {MDPI AG},
abstract = {<jats:p>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.</jats:p>},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
<jats:p>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.</jats:p>
Steenbakkers, Kim; van Boxtel, Tom; Groenenboom, Gerrit C.; Asvany, Oskar; Redlich, Britta; Schlemmer, Stephan; Brünken, Sandra
Leak-out spectroscopy as alternative method to rare-gas tagging for the Renner–Teller perturbed HCCH+ and DCCD+ ions Journal Article
In: Phys. Chem. Chem. Phys., vol. 26, no. 3, pp. 2692–2703, 2024, ISSN: 1463-9084.
@article{Steenbakkers2024,
title = {Leak-out spectroscopy as alternative method to rare-gas tagging for the Renner–Teller perturbed HCCH^{+} and DCCD^{+} ions},
author = {Kim Steenbakkers and Tom van Boxtel and Gerrit C. Groenenboom and Oskar Asvany and Britta Redlich and Stephan Schlemmer and Sandra Brünken},
doi = {10.1039/d3cp04989b},
issn = {1463-9084},
year = {2024},
date = {2024-01-17},
urldate = {2024-01-17},
journal = {Phys. Chem. Chem. Phys.},
volume = {26},
number = {3},
pages = {2692--2703},
publisher = {Royal Society of Chemistry (RSC)},
abstract = {<jats:p>Vibronic coupling effects in the low-lying bending modes of the open-shell linear ions HCCH<jats:sup>+</jats:sup> and DCCD<jats:sup>+</jats:sup> have been investigated using cryogenic infrared action spectroscopy in combination with a free electron laser.</jats:p>},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
<jats:p>Vibronic coupling effects in the low-lying bending modes of the open-shell linear ions HCCH<jats:sup>+</jats:sup> and DCCD<jats:sup>+</jats:sup> have been investigated using cryogenic infrared action spectroscopy in combination with a free electron laser.</jats:p>
2023
Changala, P. Bryan; Chen, Ning L.; Le, Hai L.; Gans, Bérenger; Steenbakkers, Kim; Salomon, Thomas; Bonah, Luis; Schroetter, Ilane; Canin, Amélie; Martin-Drumel, Marie-Aline; Jacovella, Ugo; Dartois, Emmanuel; Boyé-Péronne, Séverine; Alcaraz, Christian; Asvany, Oskar; Brünken, Sandra; Thorwirth, Sven; Schlemmer, Stephan; Goicoechea, Javier R.; Rouillé, Gaël; Sidhu, Ameek; Chown, Ryan; Putte, Dries Van De; Trahin, Boris; Alarcón, Felipe; Berné, Olivier; Habart, Emilie; Peeters, Els
Astronomical CH3+ rovibrational assignments. A combined theoretical and experimental study validating observational findings in the d203-506 UV-irradiated protoplanetary disk Journal Article
In: Astronomy & Astrophysics, vol. 680, pp. A19, 2023.
@article{2023A&A...680A..19C,
title = {Astronomical CH_{3}^{+} rovibrational assignments. A combined theoretical and experimental study validating observational findings in the d203-506 UV-irradiated protoplanetary disk},
author = {P. Bryan Changala and Ning L. Chen and Hai L. Le and Bérenger Gans and Kim Steenbakkers and Thomas Salomon and Luis Bonah and Ilane Schroetter and Amélie Canin and Marie-Aline Martin-Drumel and Ugo Jacovella and Emmanuel Dartois and Séverine Boyé-Péronne and Christian Alcaraz and Oskar Asvany and Sandra Brünken and Sven Thorwirth and Stephan Schlemmer and Javier R. Goicoechea and Gaël Rouillé and Ameek Sidhu and Ryan Chown and Dries Van De Putte and Boris Trahin and Felipe Alarcón and Olivier Berné and Emilie Habart and Els Peeters},
doi = {10.1051/0004-6361/202347765},
year = {2023},
date = {2023-12-01},
urldate = {2023-12-01},
journal = {Astronomy & Astrophysics},
volume = {680},
pages = {A19},
key = {B8,C4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
References
- Asvany and Schlemmer, “Rotational action spectroscopy of trapped molecular ions”, Phys. Chem. Chem. Phys. 23, 26602 (2021).
- Brünken, Sipilä, Chambers, Harju, Caselli, Asvany, Honingh, Kamin ́ski, et al., “H2D+ observations give an age of at least one million years for a cloud core forming Sun-like stars”, Nature 516, 219 (2014).
- Brünken, Kluge, Stoffels, Asvany, and Schlemmer, “Laboratory Rotational Spectrum of l-C3H+ and Confirmation of its Astronomical Detection”, ApJ Letters 783, L4 (2014).
- Doménech, Jusko, Schlemmer, and Asvany, “The First Laboratory Detection of Vibration-rotation Tran- sitions of 12CH+ and 13CH+ and Improved Measurement of Their Rotational Transition Frequencies”, ApJ 857, 61 (2018).
- Doménech, Schlemmer, and Asvany, “Accurate rotational rest frequencies for ammonium ion isotopo- logues”, ApJ 866, 158 (2018).
- Jusko, Asvany, Wallerstein, Brünken, and Schlemmer, “Two photon rotational action spectroscopy of cold OH at 1 ppb accuracy”, Phys. Rev. Lett. 112, 253005 (2014).
- Jusko, Stoffels, Thorwirth, Brünken, Schlemmer, and Asvany, “High-resolution vibrational and rota- tional spectroscopy of CD2H+ in a cryogenic ion trap”, J. Mol. Spectrosc. 332, 59 (2017).
- McGuire, Asvany, Brünken, and Schlemmer, “Laboratory spectroscopy techniques to enable observa- tions of interstellar ion chemistry”, Nat. Rev. Phys. 2, 402 (2020).
- Schmid, Asvany, Salomon, Thorwirth, and Schlemmer, “Leak-out Spectroscopy, a universal method of action spectroscopy in cold ion traps”, J. Phys. Chem. A 126, 8111 (2022).
- Thorwirth, Schreier, Salomon, Schlemmer, and Asvany, “Pure Rotational Spectrum of CN+”, ApJ Letters 882, L6 (2019).
