Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

Near infrared excited FT-Raman spectra of 2,2'-cyanine adsorbed onto a smooth silver electrode and of polycrystalline 2,2'-cyanine are compared with dispersive Raman spectra obtained using visible excitation to determine adsorbate structural characteristics. Raman spectra are interpreted as indicating that 2,2'-cyanine exists as a structural composite of polycrystalline and two intermolecular arrangements of cyanine monomers forming the J-aggregate. This structural model is shown to explain Raman intensity variations that depend upon dye concentration, supporting electrolyte, pH, and electrode potential. Variations of the FT-Raman relative band intensities over a surface potential range in which the surface concentration increases indicate that one of the structural conformers in the Jaggregate is thermodynamically favored at more negative potentials.