The near IR (overtone) spectra of water, H2Ondash;D2O solutions, and a glasshyphen;forming glycerol +D2O solution have been measured in the temperature range 80 to minus;30thinsp;deg;C (minus;120thinsp;deg;C for the glycerol +D2O solution) using emulsion samples to gain access to the deep supercooling range. At minus;30thinsp;deg;C the intensity attributed to weakly hydrogen bonded ndash;OH is greatly diminished and a small extrapolation in the latter case leads to a spectrum closely similar to that of the vitreous glycerol +D2O solution. This is a very broad spectrum, extending from 1.4ndash;1.65 mgr;m, which we associate with a fully bonded and immobile quasilattice in which there is a distribution of hydrogen bond strengths. The changes in intensity which occur with rise in temperature are seen to be consistent with an lsquo;lsquo;exciting across the centroidrsquo;rsquo; model (a weak bondrlarr2;strong bond exchange) suggested by Stillinger and Rahman on the basis of MD calculations. The enthalpy change for this process is found to be 3.0 kcal/mol, consistent with lighthyphen;scattering data for the hydrogen bondhyphen;breaking energy.
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