title: Resonance-enhanced two-photon ionization spectroscopy and theoretical calculations of 3,5-difluoroanisole and its Ar-containing complex.
abstract: The structure and vibrations of 3,5-difluoroanisole (3,5-DFA) in the first electronically excited (S(1)) state were studied by mass-analyzed resonant two-photon ionization (R2PI) technique as well as the quantum chemical calculations. The ab initio and density functional theory (DFT) calculations reveal that only one structure is stable for each of the S(0), S(1), and D(0) states. In the one color R2PI spectrum, the band origin of the S(1)←S(0) electronic transition (0(0) band) of 3,5-DFA is found to be 37,595±3 cm(-1). In the S(1) state, most of the bands observed are related to the in-plane ring deformation and out-of-plane bending vibrations. The adiabatic ionization energy (IE) of 3,5-DFA is determined to be 70,096±15 cm(-1) by the two color R2PI technique, in agreement with the values predicted by the DFT approaches. The dihalogen-substitution effects on the molecular structure, vibrational frequencies, and electronic transition and ionization energies were discussed in detail. The van der Waals complex of 3,5-DFA with argon (3,5-DFA···Ar) was also observed and studied. The 0(0) band of 3,5-DFA···Ar complex is red-shifted by about 9 cm(-1) with respect to that of 3,5-DFA. Both the experimental data and the calculated results indicate that the formation of 3,5-DFA···Ar complex gives only a weak influence on the properties of 3,5-DFA moiety.
authors.affiliation: Beijing National Laboratory of Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.forename: Changwu
authors.initials: C
authors.lastname: Dong
authors.forename: Min
authors.initials: M
authors.lastname: Cheng
authors.forename: Lili
authors.initials: L
authors.lastname: Hu
authors.forename: Yikui
authors.initials: Y
authors.lastname: Du
authors.forename: Qihe
authors.initials: Q
authors.lastname: Zhu
authors.forename: Cunhao
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000840:Anisoles / Q000737:chemistry*; D001128:Argon / Q000737:chemistry*; D004583:Electrons; D005464:Fluorobenzenes / Q000737:chemistry*; D013058:Mass Spectrometry; D008958:Models, Molecular; D008968:Molecular Conformation; D017785:Photons; D013057:Spectrum Analysis / Q000379:methods*; D013816:Thermodynamics; D014732:Vibration
chemical_list: D000840:Anisoles; D005464:Fluorobenzenes; D001128:Argon; C060998:anisole