Accurate Frequency Determination of Vibration–Rotation and Rotational Transitions of SiH⁺

Abstract

The fundamental SiH ion has been characterized in a collaborative work, utilizing a hollow-cathode-discharge laser-spectrometer and a cryogenic ion trap spectrometer. Twenty-three vibration-rotation transitions around 4.75 m have been detected with high accuracy. This has facilitated the first direct measurement of the pure rotational transition = 1 ← 0 at 453056.3632(4) MHz in the trap spectrometer. The measured and accurately predicted transitions enable the search for this ion in space with IR and sub-mm telescopes.

The First Laboratory Detection of Vibration-rotation Transitions of 12CH+ and 13CH+ and Improved Measurement of Their Rotational Transition Frequencies

“…The spectroscopy of CH + was facilitated by a cryogenic ion trap experiment, in which the mentioned parasitic reactants are frozen out. As the applied trapping setup (Asvany et al (2010, 2014)) and the action schemes for rovibrational as well as pure rotational spectroscopy have been thoroughly documented by Asvany et al (2014); Savić et al (2015); Jusko et al (2016, 2017); Doménech et al (2017); Stoffels et al (2016); Brünken et al (2014, 2017), only a brief description is given here. The CH + (similarly 13 CH + and CD + ) ions have been generated in a storage ion source by bombarding the precursor gas (CH 4 Linde 5.5, 13 CH 4 Sigma Aldrich 99%, or CD4 Cambridge Isotope Laboratories 99%, respectively) with electrons (with energies in the range 30-40 eV).…”

Systems Astrochemistry: A New Doctrine for Experimental Studies

“…In laboratory astrochemistry, the most commonly used in situ analytical techniques are quadrupole mass spectrometry (QMS) and Fourier-transform mid-infrared spectroscopy (FTIR). Other techniques are also becoming more popular: the use of millimeter/sub-millimeter and terahertz spectroscopy, for instance, will likely help bridge results from the laboratory to observational studies (e.g., Doménech et al, 2017;Chantzos et al, 2019;Widicus Weaver 2019;Yocum et al, 2019;Zakharenko et al, 2019;Bizzocchi et al, 2020;Stahl et al, 2020;Mifsud et al, 2021a), while in situ transmission electron microscopy (TEM) has recently been used to great effect in understanding diffusion and crystallization in ices (Kouchi et al, 2020;Tsuge et al, 2020;Kouchi et al, 2021). Although in situ techniques are useful in identifying functional groups present in the ice and sputtered or desorbed molecules in the gas phase, some of the products form a refractory solid residue which is too complex for its individual components to be resolved via FTIR spectroscopy.…”

Fingerprints of microscopic superfluidity in HHen+ clusters

“…With a suitable cw light source (most probably a quantum cascade laser) operating in that region, we intend to tackle this fundamental system in the Cologne laboratories. Even rotational spectroscopy is feasible with this action spectroscopic method [87][88][89][90]. The computed rotational constant of HHe + 2 , again at the aug-cc-pVQZ MP2 level, is B 0 = 2.37 cm −1 .…”