Study of photoionization and dissociative photoionization of carbon monoxide from ionization threshold to 38eV by using synchrotron radiation

• Published in: Journal of electron spectroscopy and related phenomena Vol. 196; pp. 181 - 186
• Main Authors: Zhao, Yujie, Cao, Maoqi, Li, Yuquan, Shan, Xiaobin, Liu, Fuyi, Sheng, Liusi, Li, Li, Liu, Wanfang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2014
• Subjects: Dissociative photoionization; Photoionization; Photoionization efficiency spectrum; Photoionization mass spectrometry; Synchrotron radiation; Photoionization mass spectrometry; Dissociative photoionization; Photoionization; Photoionization efficiency spectrum; Synchrotron radiation
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/j.elspec.2014.02.014

•The high resolution photoionization spectrum of carbon monoxide has been investigated using tunable synchrotron radiation.•This work has investigated comprehensively almost all kinds of photo excitation processes of CO in wide photon region.•The mechanisms of photoionization and dissociative photoionization of CO have been researched in detail. The vacuum-ultraviolet photoionization and dissociative photoionization of carbon monoxide in a region 14–38eV have been investigated with time-of-flight (TOF) photoionization mass spectrometry (PIMS) using tunable synchrotron radiation (SR). The adiabatic ionization energy (IE) of carbon monoxide and appearance energies (AE) for its fragment ions in different states are determined by measurements of photoionization efficiency spectra (PIES). Ab initio calculations have been performed to investigate the reaction mechanism of dissociative photoionization of carbon monoxide. On the basis of experimental and predicted theoretical results, the mechanisms of photoionization and dissociative photoionization of molecular CO are discussed, and sixteen dissociative photoionization processes are proposed. The equilibrium geometries and harmonic vibrational frequencies of CO molecule, and its parent cation were calculated by using MP2 (full) method. The differences of configurations between them are also discussed on the basis of theoretical calculations. According to our results, the experimental IE of CO molecule, and dissociation energies (Ed) of possible dissociative channels are in reasonable agreement with the calculated values of the proposed photodissociation channels.