Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (4): 893-900.doi: 10.3866/PKU.WHXB201601293

• ARTICLE • Previous Articles     Next Articles

Rotamers of 2, 5-Difluorophenol Studied Using Mass-Analyzed Threshold Ionization Spectroscopy

Pei-Ying WU1,2,Sheng-Yuan TZENG1,*(),Ching-Yun TSAI1,3,Wen-Bih TZENG1,3   

  1. 1 Laboratory for Mass Spectrometric and Spectroscopic Studies of Biomolecules, Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617
    2 Department of Chemistry, National Taiwan University, Taipei 10617
    3 Department of Chemistry, National Taiwan Normal University, Taipei 11677
  • Received:2015-11-30 Published:2016-04-07
  • Contact: Sheng-Yuan TZENG
  • Supported by:
    the Ministry of Science and Technology of the Republic of China(MOST-103-2113-M-001-009, MOST-104-2113-M-001-014)


We applied resonant two-photon ionization (R2PI) and mass-analyzed threshold ionization (MATI) techniques to record the vibronic and cationic spectra of 2, 5-difluorophenol. The distinct bands at 36448 and 36743 cm-1 were confirmed as the origins of the S1S0 electronic transition of the cis and trans rotamers, respectively. The corresponding adiabatic ionization energies were found to be 71164 and 71476 cm-1 for these two rotameric species. The observed spectral features mainly result from the in-plane ring deformation and substituent-sensitive bending vibrations. Spectral analysis suggests that the molecular geometry and vibrational coordinates of the cation in the D0 state resemble those of the neutral species in the S1 state for both cis and trans rotamers.

Key words: Resonant two-photon ionization technique, Threshold ionization, Vibronic spectrum, Cation spectrum, 2, 5-Difluorophenol


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