Vibrational spectral signature of the proton defect in the three-dimensional H + (H 2 O) 21 cluster

Abstract

Blackjack water cluster detected Spectroscopy of protonated water clusters has played a pivotal role in elucidating the molecular arrangement of acid solutions. Whereas bulk liquids manifest broad spectral features, the cluster bands tend to be sharper. The 21-membered water cluster has for decades inspired particular interest on account of its stability and its place in the transition from two-dimensional to three-dimensional hydrogen-bonding network motifs, but the spectral signature of its bound proton has proved elusive. Fournier et al. have now detected this long-sought vibrational feature by applying an innovative ion cooling technique. Science , this issue p. 1009