Probing the hydrogen-bond network of water via time-resolved soft X-ray spectroscopy.
We report time-resolved studies of hydrogen bonding in liquid H(2)O, in response to direct excitation of the O-H stretch mode at 3 mum, probed via soft X-ray absorption spectroscopy at the oxygen K-edge. This approach employs a newly developed nanofluidic cell for transient soft X-ray spectroscopy in the liquid phase. Distinct changes in the near-edge spectral region (XANES) are observed, and are indicative of a transient temperature rise of 10 K following transient laser excitation and rapid thermalization of vibrational energy. The rapid heating occurs at constant volume and the associated increase in internal pressure, estimated to be 8 MPa, is manifested by distinct spectral changes that differ from those induced by temperature alone. We conclude that the near-edge spectral shape of the oxygen K-edge is a sensitive probe of internal pressure, opening new possibilities for testing the validity of water models and providing new insight into the nature of hydrogen bonding in water.
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. nhuse@lbl.gov
Nils
N
Huse
Haidan
H
Wen
Dennis
D
Nordlund
Erzsi
E
Szilagyi
Dan
D
Daranciang
Timothy A
TA
Miller
Anders
A
Nilsson
Robert W
RW
Schoenlein
Aaron M
AM
Lindenberg
D000042:Absorption; D006860:Hydrogen Bonding; D011312:Pressure; D013059:Spectrum Analysis, Raman; D013696:Temperature; D013997:Time Factors; D014732:Vibration; D014867:Water / Q000737:chemistry*; D014965:X-Rays
D014867:Water