A cluster study of anionic hydration: Spectroscopic characterization of the I-center dot W-n, 1 <= n <= 3, supramolecular complexes at the primary steps of solvation

By isolating I-.Wn clusters in the gas phase, we eliminate the fluctuations and heterogeneity present in solution, allowing us to follow how water mol ecules (W) sequentially lock into position and form supramolecular complexe s at the early stages of hydration: We report vibrational predissociation s pectra of the I-.Wn 1 less than or equal to n less than or equal to 3, comp lexes quenched close to their minimum energy configurations by complexation with argon. Structures are extracted from these spectra by comparison with the band patterns expected for the various geometries.