Vibrational response of hydrogen-bonded interfacial water is dominated by intramolecular coupling.
Using the surface-specific vibrational technique of vibrational sum-frequency generation, we reveal that the double-peaked structure in the vibrational spectrum of hydrogen-bonded interfacial water molecules originates from vibrational coupling between the stretch and bending overtone, rather than from structural effects. This is demonstrated by isotopic dilution experiments, which reveal a smooth transition from two peaks to one peak, as D2O is converted into HDO. Our results show that the water interface is structurally more homogeneous than previously thought.
FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ, Amsterdam, The Netherlands.
Maria
M
Sovago
R Kramer
RK
Campen
George W H
GW
Wurpel
Michiel
M
Müller
Huib J
HJ
Bakker
Mischa
M
Bonn
D006860:Hydrogen Bonding; D013055:Spectrophotometry, Infrared / Q000379:methods; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D014867:Water