Electronic spectra of a homo-molecular but inequivalent dimer ion, (C6H5OH)+2, are measured by photodissociation spectroscopy. A broad band appeared in the 340-440 nm region is characteristic of the C ← X transition of a phenol ion chromophore, suggesting that the dimer ion consists of a phenol ion and a neutral phenol. No strong band is observed in the 450-1400 nm region, whereas other aromatic dimer ions usually show charge resonance bands in near-infrared region. Owing to the geometrical constraint of an O-H ⋯ O hydrogen bond in (C6H5OH)+2, the two aromatic rings cannot be in a parallel configuration suitable for the resonance interaction.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry