Vibrational spectroscopy of large water clusters of known size
Max–Planck–Institut für Strömungsforschung, 37073 Göttingen, Germany
Corresponding author: a firstname.lastname@example.org
Published online: 3 July 2003
The structure of large water clusters of known size distributions is investigated by vibrational spectroscopy of the OH stretch mode. The water clusters are predissociated by a pulsed tunable infrared optical parametrical oscillator (OPO) in the frequency range cm-1. Their fragments are detected off-axis by electron impact ionization and mass analyzed by a quadrupole mass spectrometer. The largest ion signal stems from the neutral water hexamer fragment. The ion yield is investigated at certain wavelengths while the size of the clusters is varied, and for certain sizes complete absorption spectra of the OH stretch motion are measured. Fingerprints of the different coordination types of the water molecules in the clusters are found and it turns out that our method is especially sensitive to amorphous structures with frequencies shifting in the range of cm-1.
PACS: 36.40.Mr – Spectroscopy and geometrical structure of clusters / 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003