Differences in the Vibrational Dynamics of H(2)O and D(2)O: Observation of Symmetric and Antisymmetric Stretching Vibrations in Heavy Water.
Water's ability to donate and accept hydrogen bonds leads to unique and complex collective dynamical phenomena associated with its hydrogen-bond network. It is appreciated that the vibrations governing liquid water's molecular dynamics are delocalized, with nuclear motion evolving coherently over the span of several molecules. Using two-dimensional infrared spectroscopy, we have found that the nuclear motions of heavy water, D2O, are qualitatively different than those of H2O. The nonlinear spectrum of liquid D2O reveals distinct O-D stretching resonances, in contrast to H2O. Furthermore, our data indicates that condensed-phase O-D vibrations have a different character than those in the gas phase, which we understand in terms of weakly delocalized symmetric and antisymmetric stretching vibrations. This difference in molecular dynamics reflects the shift in the balance between intra- and intermolecular couplings upon deuteration, an effect which can be understood in terms of the anharmonicity of the nuclear potential energy surface.
Department of Chemistry, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.|Department of Chemistry, James Frank Institute, and The Institute for Biophysical Dynamics, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
Luigi
L
De Marco
Department of Chemistry, James Frank Institute, and The Institute for Biophysical Dynamics, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
William
W
Carpenter
Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30322, United States.
Hanchao
H
Liu
Department of Chemistry, James Frank Institute, and The Institute for Biophysical Dynamics, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
Rajib
R
Biswas
Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University , 1515 Dickey Drive, Atlanta, Georgia 30322, United States.
Joel M
JM
Bowman
Department of Chemistry, James Frank Institute, and The Institute for Biophysical Dynamics, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
Andrei
A
Tokmakoff