Temperature-induced disordering of the hydrophobic hydration shell of Kr and Xe

X-ray absorption fine structure spectroscopy has been used to investigate the temperature dependence of the hydrophobic hydration shell of the noble gases krypton and xenon in the range 277 to 368 K. These data provide clear experimental evidence for a systematic thermal perturbation and associated entropic gain that have come to form a critical component of conventional models of non-polar moiety hydration. Further, these measurements of this structure provide insight into the subtleties of this complex non-polar hydration mechanism.