Vibrational Structure of Vinyl Chloride Cation Studied by Using One-Photon Zero-Kinetic Energy Photoelectron Spectroscopy

Abstract

The vibrational structure of vinyl chloride cation, CH(2)CHCl+ (X(2)A' '), has been studied by vacuum ultraviolet (VUV) zero-kinetic energy (ZEKE) photoelectron spectroscopy. Among nine symmetric vibrational modes, the fundamental frequencies of six modes have been determined. The first overtone of the out-of-plane CH(2) twist vibrational mode has been also measured. In addition to these, the combination and overtone bands of the above vibrational modes about 4500 cm(-1) above the ground state have been observed in the ZEKE spectrum. The vibrational band intensities of the ZEKE spectrum can be described approximately by the Franck-Condon factors with harmonic approximation. The ZEKE spectrum has been assigned based on the harmonic frequencies and Franck-Condon factors from theoretical calculations. The ionization energy (IE) of CH(2)CHCl is determined as 80705.5 +/- 2.5 (cm(-1)) or 10.0062 +/- 0.0003 (eV).

Multireference Configuration Interaction Study of the Vibronic Transitions and Photodissociation of Vinyl Bromide and Vinyl Chloride Radical Cations in the Second Excited State

“…As for the ground state, Zhang et al measured the ZEKE spectrum of the cation and derived fundamental vibrational frequencies, which were compared with vibrational frequencies calculated using Møller-Plesset perturbation theory (MP2). 57 The present calculation shows very good agreement with their experimental and calculated values. For the B ˜state, most of the calculated vibrational frequencies in the present study were 20% larger than the corresponding values published by Lee et al 22 They derived six vibrational frequencies from the MATI-PFY spectrum and their calculated values agreed closely with them.…”

“…The vibrational frequencies of CH 2 CHCl + are summarized in Table . As for the ground state, Zhang et al measured the ZEKE spectrum of the cation and derived fundamental vibrational frequencies, which were compared with vibrational frequencies calculated using Møller−Plesset perturbation theory (MP2) . The present calculation shows very good agreement with their experimental and calculated values.…”

Cl-Loss Dynamics of Vinyl Chloride Cations in the B2A″ State: Role of the C2A′ State

“…Removing an electron from its outer orbitals, such as the 3a″, 13a′, 2a″, and 12a′ orbitals, produces a C 2 H 3 Cl + cation in one of several possible electronic states, including X 2 A″, A 2 A′, B 2 A″, and C 2 A′. The spectroscopy of C 2 H 3 Cl + cation has been extensively investigated. − In photoelectron spectroscopy (PES) , and threshold photoelectron spectroscopy (TPES), a series of vibrational bands were observed for the X 2 A″ and A 2 A′ states, while the B 2 A″ and C 2 A′ bands were structureless and severely overlapped. The adiabatic ionization energy of C 2 H 3 Cl was determined to be 10.0062 ± 0.0003 eV using high-resolution zero-kinetic-energy (ZEKE) PES .…”

“…The spectroscopy of C 2 H 3 Cl + cation has been extensively investigated. − In photoelectron spectroscopy (PES) , and threshold photoelectron spectroscopy (TPES), a series of vibrational bands were observed for the X 2 A″ and A 2 A′ states, while the B 2 A″ and C 2 A′ bands were structureless and severely overlapped. The adiabatic ionization energy of C 2 H 3 Cl was determined to be 10.0062 ± 0.0003 eV using high-resolution zero-kinetic-energy (ZEKE) PES . The ionization energy of the A 2 A′ and B 2 A″ states was measured using mass-analyzed threshold ionization (MATI) and MATI photodissociation yield (PDY) spectroscopy .…”

“…The adiabatic ionization energy of C 2 H 3 Cl was determined to be 10.0062 ± 0.0003 eV using high-resolution zero-kinetic-energy (ZEKE) PES. 10 The ionization energy of the A 2 A′ and B 2 A″ states was measured using mass-analyzed threshold ionization (MATI) 11 and MATI photodissociation yield (PDY) spectroscopy. 12 In the MATI-PDY spectrum, several vibrational peaks were observed in the lower-energy region of the B 2 A″ state, implying that the ionic state has a shallow potential well.…”