title: Quantum-chemical study of the structure of the acetyl fluoride molecule in the ground and lowest excited singlet and triplet electronic states.
abstract: The structure of the conformationally flexible acetyl fluoride molecule (CH3CFO and CD3CFO) in the ground (S0) and lowest excited triplet (T1) and singlet (S1) electronic states was calculated by different quantum-chemical methods (RHF, UHF, MP2, CASSCF). The equilibrium geometric parameters and harmonic vibrational frequencies of the molecules in these electronic states were estimated. The calculations demonstrated that the electronic excitation causes considerable conformational changes involving the rotation of the CH3(CD3) top and a substantial deviation of the CCFO carbonyl fragment from planarity. For large-amplitude vibrations, namely, for the torsional vibration in the S0 state and the torsional and inversion (nonplanar carbonyl fragment) vibrations in the T1 and S1 states, the quantum-mechanical problems were solved in one-dimensional (1D) and two-dimensional (2D) approximations. The results of calculations are in good agreement with experimental data.
authors.affiliation: Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119899, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Kudich
authors.forename: V A
authors.initials: VA
authors.lastname: Bataev
authors.forename: A V
authors.initials: AV
authors.lastname: Abramenkov
authors.forename: I A
authors.initials: IA
authors.lastname: Godunov
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry*; D003903:Deuterium; D004563:Electrochemistry; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics
chemical_list: D006845:Hydrocarbons, Fluorinated; C075898:fluoroacetaldehyde; D003903:Deuterium; D000079:Acetaldehyde