Resonance enhanced multiphoton ionization and time-of-flight mass spectra of jet-cooled 3-chlorophenol dimer

The resonance enhanced multiphoton ionization (REMPI) excitation spectrum of jet-cooled 3-chlorophenol (3-ClP) was measured in combination with time-of-flight (TOF) mass spectrometry. In the TOF mass spectrum, 3-ClP, 3-ClP dimer and 3-ClP-water cluster cations were observed. The REMPI excitation spectrum of the dimer was observed for the first time. The low-frequency intermolecular vibrations show the hydrogen bonding of the dimer of 3-ClP to be similar to the phenol dimer. The hydrogen bonding was found to be weaker than that of the phenol dimer. The structures of the dimer and the 3-ClP-water cluster were obtained from ab initio calculations, which suggest that dimer has a sandwich-type structure with weak hydrogen bond. q 2005 Elsevier B.V. All rights reserved