SPECTROSCOPIC STUDY OF THE STEPWISE SOLVATION OF $CN^{-}\cdot (H_{2}O)_{n}$ VIA IR-VPS

IR Vibrational Predissociation Spectra of $CN^{-}\\cdot (H_{2}O)_{n}$, anionic clusters, where n=2 through 6, were obtained in the 2900 to $3900 cm^{-1}$ region. The vibrational frequencies of the water molecules serve as a probe of the hydrogen bonding network, which is determined by the competition of solvent-anion and solvent-solvent interactions. The size dependence of the spectral features suggests the contribution of second binding site for n $> 4$, and the possibility of a temperature induced proton-transfer reaction for the n=4 cluster.