| Summary: | 碩士 === 國立臺中教育大學 === 科學教育與應用學系碩士在職專班 === 105 === The photoelectron spectra of dimethyl ether, ethyl methyl ether, and acetic acid were studied by theoretical calculations. The equilibrium geometries and harmonic vibrational frequencies of the three molecules and their cations were computed by using the density functional theory (B3LYP and M06-2X functionals) associated with the aug-cc-pVTZ basis set. The Franck-Condon factors were calculated and the photoelectron spectra of the target molecules were simulated. For dimethyl ether and ethyl methyl ether, their Franck-Condon factors were very small due to drastic geometrical changes, and we computed their photoelectron spectra by using the geometries at the saddle point. The energies of the molecules and cations were also calculated by using the CCSD(T) method associated with the basis sets of aug-cc-pVXZ (X = D, T, Q, 5), which were extrapolated to the complete basis set limit in order to obtain the adiabatic ionization energies. The simulated photoelectron spectra of dimethyl ether, ethyl methyl ether, and acetic acid are in agreement with experiments. The calculated ionization energies are also consistent with experimental values, with deviations of -0.093, -0.003, and -0.007 eV for ethyl methyl ether, dimethyl ether and acetic acid, respectively.
|
|---|
