The second harmonic (SH) generation efficiency upon compression of insoluble rhodamine C18 and fluorescein O322 monolayers at the air/water interface has been measured. The SH intensity dependence on area per molecule clearly varied for four main regions: expanded monolayer, expanded-condensed transition region, condensed monolayer and collapse point. This SH intensity dependence was similar with the π-A isotherm for both molecules. The SH intensity change would be explained with a model of interactions of dye chromophores based on the dipole-dipole correlation, CH-π interaction, aggregates of electronic transition moments and formation of large order π-conjugated system.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry