Open AccessTemperature dependence of the isotope chemistry of the heavy elements.
Author(s) -
Jacob Bigeleisen
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.18.9393
Subject(s) - isotope , chemistry , kinetic isotope effect , isotope fractionation , equilibrium fractionation , fractionation , heavy ion , stable isotope ratio , mass independent fractionation , deuterium , isotope geochemistry , radiochemistry , ion , atomic physics , nuclear physics , physics , chromatography , organic chemistry
The temperature coefficient of equilibrium isotope fractionation in the heavy elements is shown to be larger at high temperatures than that expected from the well-studied vibrational isotope effects. The difference in the isotopic behavior of the heavy elements as compared with the light elements is due to the large nuclear isotope field shifts in the heavy elements. The field shifts introduce new mechanisms for maxima, minima, crossovers, and large mass-independent isotope effects in the isotope chemistry of the heavy elements. The generalizations are illustrated by the temperature dependence of the isotopic fractionation in the redox reaction between U(VI) and U(IV) ions.