Isomer-specific photofragmentation of C3H3+ at the carbon K-edge

• Published in: Physical chemistry chemical physics : PCCP 2024-05, Vol.26 (21), p.15519-15529
• Main Authors: Reinwardt, Simon, Cieslik, Patrick, Buhr, Ticia, Perry-Sassmannshausen, Alexander, Schippers, Stefan, Müller, Alfred, Trinter, Florian, Martins, Michael
• Format: Article
• Language: English
• Subjects: Absorption spectra; Carbon; Cyclotron resonance; Density functional theory; Electron cyclotron resonance; Electronic structure; Fine structure; Ion beams; Ion sources; Isomers; Molecular ions; Molecular structure; Photoexcitation; Photoionization; Photon beams; Photons; Spectrum analysis; Time dependence; X ray absorption
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d4cp00370e

Individual fingerprints of different isomers of C3H3+ cations have been identified by studying photoionization, photoexcitation, and photofragmentation of C3H3+ near the carbon K-edge. The experiment was performed employing the photon-ion merged-beams technique at the photon-ion spectrometer at PETRA III (PIPE). This technique is a variant of near-edge X-ray absorption fine-structure spectroscopy, which is particularly sensitive to the 1s → π* excitation. The C3H3+ primary ions were generated by an electron cyclotron resonance ion source. C3Hn2+ product ions with n = 0, 1, 2, and 3 were observed for photon energies in the range of 279.0 eV to 295.2 eV. The experimental spectra are interpreted with the aid of theoretical calculations within the framework of time-dependent density functional theory. To this end, absorption spectra have been calculated for three different constitutional isomers of C3H3+. We find that our experimental approach offers a new possibility to study at the same time details of the electronic structure and of the geometry of molecular ions such as C3H3+.