Fluorescence spectroscopy of jet-cooled o-fluoroanisole: Mixing through Duschinsky effect and Fermi resonance

Abstract

Laser-induced fluorescence (LIF) excitation, UV-UV hole burning, and single vibronic level fluorescence (SVLF) spectra of jet-cooled o-fluoroanisole (o-FA) were measured. The most intense lowest-frequency band at 36 612 cm(-1) was assigned to the origin band of the most stable trans conformer. The UV-UV hole-burning spectrum demonstrated that the prominent bands in the LIF excitation spectrum were responsible for the trans conformer. The metastable non-planar conformer was not observed in the spectra. The vibrational band assignments were performed with the aid of quantum chemical calculations at the B3LYP/cc-pVTZ and CIS/6-311G(d,p) levels. The precise analysis of the SVLF spectra indicated that strong vibrational mixing through the Duschinsky effect and the Fermi resonance occurs in the S(1) state.

Two-color resonant two-photon ionization and mass-analyzed threshold ionization spectroscopy of o-chloroanisole

“…The general features of these two spectra are nearly identical with the same E 1 of 35 745 ± 2 cm −1 . Similar to the cases of o-dimethoxybenzene [23] and o-fluoroanisole [24,25], only one stable isomer of o-chloroanisole is found to involve in the present R2PI and MATI experiments. The configuration interaction singles (CIS), time-dependent Becke three-parameter functional with the Lee-Yang-Parr functional (TD-B3LYP), and TD-B3PW91 methods with the aug-cc-pVDZ basis set predict the E 1 's of 43 723, 36 850, and 37 176 cm −1 , corresponding to overestimations of 22.3, 3.1, and 4.0%, respectively.…”

“…As for o-fluoroanisole [24,25] and o-chloroanisole, only the trans rotamers involve in the photoexcitation and photoionization processes of the R2PI and MATI experiments. These results indicate that the nature of the substituent can affect the through-space interaction between the two substituents at the ortho position.…”

Ionization energy and active cation vibrations of trans -2-fluorostyrene

“…1(a). The spectral assignment was done by comparing these data with the experimental values of literature values of 2-fluorophenylacetylene [15] and trans-2-fluoroanisole [16] as well as the predicted vibrational frequencies from the time-dependent Becke three-parameter with the Lee-Yang-Parr functional (TD-B3LYP) calculations with the 6-311++G(d,p) basis set. The numbering system of the normal vibrations follows that used by Varsanyi and Szoke [4,17] for benzene derivatives and is based on Wilson's notations [18].…”

Two-Color Resonant Two-Photon Mass-Analyzed Threshold Ionization of 2,4-Difluoroanisole and the Additivity Relation of Ionization Energy

“…A clearer understanding of the chemical properties of fluorinated compounds is important for drug development . Many fluorine-substituted benzene derivatives − have been studied using various spectroscopic methods. Due to the nature and different locations of the substituents, multiply substituted benzenes may possess structural isomers with overlapping spectral ranges. , A reasonably high spectral resolution is required in spectroscopy methods for recording the molecular spectra of specific isomeric species.…”