Water clusters are formed in helium droplets via the sequential capture of monomers. One or two neon atoms are added to each droplet prior to the addition of water. The infrared spectrum of the droplet ensemble reveals several signatures of polar, water tetramer clusters having dipole moments between 2 and 3 Debye. Comparison with ab initio computations supports the assignment of the cluster networks to non-cyclic “3+1” clusters, which are ~5.3 kcal/mol less stable than the global minimum non-polar cyclic tetramer. The (H2O)3Ne + H2O ring insertion barrier is sufficiently large, such that evaporative helium cooling is capable of kinetically quenching the non-equilibrium tetramer system prior to its rearrangement to the lower energy cyclic species. To this end, the reported process results in the formation of exotic water cluster networks that are higher in energy than the most stable gas phase analogs.

Formation of exotic networks of water clusters in helium droplets facilitated by the presence of neon atoms

253rd National Meeting (2017)

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