D/H isotope fractionation in the aqueous hydroxide ion

Abstract

We studied deuterium-to-hydrogen isotope effects in aqueous hydroxide ion at the HF/6-31G(d) and B3LYP/6-31+G(d) levels of theory, using OH-(H 2O)39 clusters as model systems. Both the theoretical levels indicated that the hydroxide hydrogen atom and hydrogen atoms of waters hydrogen-bonded to the hydroxide oxygen atom tended to be depleted in the heavier hydrogen isotope relative to hydrogen atoms of bulk water and the degree of deuterium depletion was more substantial in the former than in the latter hydrogen atoms. Copyright © 2009 by The Geochemical Society of Japan.