Characterization of gas-phase HCl-H2O clusters using pulsed infrared cavity ringdown spectroscopy

Using the Berkeley medium-resolution pulsed cavity ringdown spectrometer we have observed the HCl stretch spectrum of the HCl-H2O dimer and DCl stretch mode of the completely deuterated analog. The shifts from the free HCl stretch are consistent with theory and Ar matrix isolation work. Rotational structure was obtained for the deuterated cluster and spectroscopic constants for both chlorine isotopomers determined. Cluster number densities were determined to be slightly lower than found for the pure water dimer under similar conditions