Gas-Phase Infrared Spectrum of the Protonated Water Dimer

+ See all authors and affiliations

Science  28 Feb 2003:
Vol. 299, Issue 5611, pp. 1375-1377
DOI: 10.1126/science.1081634

You are currently viewing the abstract.

View Full Text


The protonated water dimer is a prototypical system for the study of proton transfer in aqueous solution. We report infrared photodissociation spectra of cooled H+(H2O)2 [and D+(D2O2] ions, measured between 620 and 1900 wave numbers (cm−1). The experiment directly probes the shared proton region of the potential energy surface and reveals three strong bands below 1600 cm−1 and one at 1740 cm−1 (for H5O2 +). From a comparison to multidimensional quantum calculations, the three lower energy bands were assigned to stretching and bending fundamentals involving the O⋯H+⋯O moiety, and the highest energy band was assigned to a terminal water bend. These results highlight the importance of intermode coupling in shared proton systems.

  • * To whom correspondence should be addressed. E-mail: asmis{at} (K.R.A.); dan{at}

View Full Text