Threshold photoelectron spectrum of CH_(2)F_(2)in the photon energy range of 12.45-14.10 eV was re-investigated by means of a combination of photo-electron-photoion coincidence experiments and density functional theor...Threshold photoelectron spectrum of CH_(2)F_(2)in the photon energy range of 12.45-14.10 eV was re-investigated by means of a combination of photo-electron-photoion coincidence experiments and density functional theory calculations.A series of vibrational peaks were distinctly observed in this range.Using optimized geometries and vibrational frequencies of the CH_(2)F_(2)neutral and its cation in ground state at the M06-2X/cc-pVTZ level of theory,Franck-Condon factor simulations were conducted.Taking into account anharmonicity influences,a perfect agreement between the simulated and experimental spectra has been achieved.From the reliable vibrational assignments,adiabatic and vertical ionization energies of CH_(2)F_(2)are derived as 12.371±0.010 eV and 13.281±0.010 eV,respectively.In addition,the experimental frequencies of four vibrational modes with ai symmetry for CH_(2)F_(2)+(X^(2)B_(1))ions are determined.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22473104 and 22073088).
文摘Threshold photoelectron spectrum of CH_(2)F_(2)in the photon energy range of 12.45-14.10 eV was re-investigated by means of a combination of photo-electron-photoion coincidence experiments and density functional theory calculations.A series of vibrational peaks were distinctly observed in this range.Using optimized geometries and vibrational frequencies of the CH_(2)F_(2)neutral and its cation in ground state at the M06-2X/cc-pVTZ level of theory,Franck-Condon factor simulations were conducted.Taking into account anharmonicity influences,a perfect agreement between the simulated and experimental spectra has been achieved.From the reliable vibrational assignments,adiabatic and vertical ionization energies of CH_(2)F_(2)are derived as 12.371±0.010 eV and 13.281±0.010 eV,respectively.In addition,the experimental frequencies of four vibrational modes with ai symmetry for CH_(2)F_(2)+(X^(2)B_(1))ions are determined.