Vacuum-Ultraviolet Photoionization Measurement and ab Initio Calculation of the Ionization Energy of Gas-Phase SiO₂

Abstract

In this work we report on the detection and vacuum-ultraviolet (VUV) photoionization of gas-phase SiO(2) generated in situ via laser ablation of silicon in a CO(2) molecular beam. The resulting species are investigated by single-photon ionization with tunable VUV synchrotron radiation and mass analyzed using reflectron mass spectrometry. Photoionization efficiency (PIE) curves are recorded for SiO and SiO(2), and ionization energy estimates are revealed from such measurements. A state-to-state ionization energy of 12.60 +/- 0.05 eV is recorded by fitting two prominent peaks in the PIE curve for the following process: (1)Sigma O-Si-O --> (2)Pi(g) [O-Si-O](+). Electronic structure calculations aid in the interpretation of the photoionization process and allow for identification of the symmetric stretch of (2)Pi(g) [O-Si-O](+), which is observed in the PIE spectrum to be 0.11 eV (890 cm(-1)) above the ground state of the cation and agrees with the 892 cm(-1) symmetric stretch frequency calculated at the CCSD(T)/aug-cc-pVTZ level.

IP determination and 1+1 REMPI spectrum of SiO at 210–220 nm in an ion trap: Implications for SiO+ ion trap loading

“…Assuming that the 17 meV depression of the IP due to the field is the extreme case and given that most molecules that we ionize will be generated under weaker fields, we can estimate that the actual IP is 11.59(1) eV. This value is within error bounds of the most reliable previous measurements [4][5][6][7]. Interestingly, the most accurate values obtained with PES[6] (11.61(1) eV) and Rydberg formula fit [5] of the n=4-16 (11.584(11) eV) disagree with each other and our measurement is halfway between those and within error bounds of both of them.…”

DETERMINATION OF IONIZATION ENERGIES OF CnN (n= 4-12): VACUUM ULTRAVIOLET PHOTOIONIZATION EXPERIMENTS AND THEORETICAL CALCULATIONS

“…The experiments are performed on a laser ablation apparatus coupled to a 3 m monochromator at the Chemical Dynamics Beamline (9.0.2) at the Advanced Light Source. The experimental apparatus used for the cluster production is the same as used recently for preparation of gas phase SiO 2 (Kostko et al 2009) and carbon clusters (Nicolas et al 2006). It consists of a laser ablation molecular beam cluster source and a reflectron time-of-flight (TOF) mass spectrometer.…”

From atoms to aerosols: probing clusters and nanoparticles with synchrotron based mass spectrometry and X-ray spectroscopy

“…2a). 8 Laser ablation and reaction of metal, 9, 10 carbon 11 and silicon clusters, 12,13 hot nozzle reactions of radicals and molecules leading to polycyclic aromatic hydrocarbons, [14][15][16][17][18][19][20][21][22] and even a mini shock tube 23 to examine high temperature and pressure reactions have utilized this instrument. For the work described here, a CW nozzle with variable openings, coupled to different sublimation sources have been adapted to generate various complexes and clusters.…”