Hydrogen Bonding in Supercritical Water. 1. Experimental Results

The upper temperature limit for the existence of hydrogen bonding in supercritical water is discussed with respect to the recent statement by Postorino et aL8 about hydrogen bonds disappearing at 673 K. This paper demonstrates, on the contrary, that hydrogen bonds in supercritical water can be observed experimentally at least up to 800 K using both spectroscopic and diffraction techniques, yet it may be predicted that hydrogen bonding persists to even higher temperatures. An attempt has been made to estimate quantitatively the temperature dependence of the degree of hydrogen bonding. I.