Microstructure ofJ-band-forming cyanine dye monolayer probed by means of second-harmonic generation

Abstract
We have determined the microscopic symmetry of the J-band-forming amphiphatic cyanine dye (S120) to be C2 by means of second-harmonic generation. We also demonstrate that the macroscopic distribution of the J aggregates is not isotropic, a result that facilitates our determination of the microscopic symmetry.