Thermal effects on energetics and dynamics in water cluster anions (H2O)n-

The electron binding energies and relaxation dynamics of water cluster anions (H2O)(n)(-) (11 <= n <= 80) formed in co-expansions with neon were investigated using one-photon and time-resolved photoelectron imaging. Unlike previous experiments with argon, water cluster anions exhibit only one isomer class, the tightly bound isomer I with approximately the same binding energy as clusters formed in argon. This result, along with a decrease in the internal conversion lifetime of excited (H2O)(n)(-) (25 <= n <= 40), indicates that clusters are vibrationally warmer when formed in neon. Over the ranges studied, the vertical detachment energies and lifetimes appear to converge to previously reported values. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3689439]