VIBRATIONAL AND ROTATIONAL ACTION SPECTROSCOPY OF H₂C₃H⁺

Silva, Weslley G. D. P.

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https://hdl.handle.net/2142/122366 Copy

Description

Title

VIBRATIONAL AND ROTATIONAL ACTION SPECTROSCOPY OF H₂C₃H⁺

Author(s)

Silva, Weslley G. D. P.

Contributor(s)

• Asvany, Oskar
• Schlemmer, Stephan
• Plaar, Eline
• Doménech, José Luis
• Gupta, Divita

Issue Date

2023-06-22

Keyword(s)

Mini-symposium: Spectroscopy with Cryogenic Ion Traps

Abstract

The high-resolution rovibrational and pure rotational spectra spectra of H₂C₃H⁺ are reported here for the first time. The spectra were collected in a 4K 22-pole cryogenic ion trap (COLTRAP) instrument using the novel leak-out spectroscopy (LOS) method.ᵃ Rovibrational signatures within the fundamental ν₁ (C-H stretch) and the combination ν₃+ν₅ (C-C stretches) bands were detected in the 3 µm spectral region using a continuous wave optical parametric oscillator and were successfully assigned, aided by previous theoretical calculations.ᵇ These observations allowed accurate spectroscopic constants for the ground and vibrationally excited states to be determined. Significant differences were observed in the values of the rotational constant A, which decreases by about 2.7% and 5.0% in the ν₁ and ν₃+ν₅ bands, respectively, in comparison to ν₀. By analyzing the changes in A, information about the molecular structure of H₂C₃H⁺ upon excitation of the C-H and C-C stretches was obtained, which indicates that the HCH angle may have an increase of approximately 3◦ in ν₁ and 6◦ in ν₃+ν₅. Guided by the ground state constants obtained from the infrared (IR) measurements, 14 pure rotational lines were observed in the 90-200 GHz frequency range using a double resonance scheme, in which the ions are excited simultaneously by the IR and a mm-wave radiation. These rotational measurements allowed even more accurate ground state spectroscopic parameters to be determined and open up the possibility for the first (radio)astronomical search of H₂C₃H⁺ in the interstellar medium. Finally, the capability of the novel LOS method in isolating isomers in the ion trap will be discussed with a focus on the abundances of H₂C₃H⁺ and its cyclic sibling, c-C₃H₃⁺

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122366

DOI

https://doi.org/10.15278/isms.2023.6914

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