Characterisation of the ground X⁺²Π_Ω and first excited A⁺²Σ⁺ electronic states of MgO⁺ by high-resolution photoelectron spectroscopy
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Date
2024-07-28Type
- Journal Article
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Abstract
Despite the importance of MgO⁺ for understanding the electronic structure and chemical bonds in alkaline-earth metal oxides and its potential astrophysical relevance, hardly any spectroscopic information is available on this molecular cation. We report on a high-resolution photoelectron spectroscopic study of MgO using a resonant (1 + 1′) two-photon excitation scheme in combination with PFI-ZEKE photoelectron spectroscopy. By carrying out the resonant excitation via selected rotational levels of several intermediate states of different electronic configurations, total electronic spins, and internuclear distances, a broad range of vibrational levels of the X⁺²Π_Ω (Ω = 3/2, 1/2) ground and A⁺²Σ⁺ first excited states of MgO⁺ were observed for the first time. The new data provide a full characterisation of the rovibronic level structure of MgO⁺ up to 2 eV (16 000 cm⁻¹) of internal energy. A full set of vibrational, rotational and spin–orbit-coupling molecular constants were extracted for these two electronic states. The adiabatic ionisation energy and the singlet–triplet interval of ²⁴Mg¹⁶O were determined to be 64 577.65(20) cm⁻¹ and 2492.4(3) cm⁻¹, respectively. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000682107Publication status
publishedExternal links
Journal / series
Physical Chemistry Chemical PhysicsVolume
Pages / Article No.
Publisher
Royal Society of ChemistryOrganisational unit
03449 - Merkt, Frédéric / Merkt, Frédéric
Funding
200478 - Precision measurements with cold molecules: Rydberg states, ions and photoionization (SNF)
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