NLO-active Y-shaped ferrocene conjugated imidazole chromophores as precursors for SHG polymeric films

New Y-shaped ferrocene conjugated imidazole chromophores were prepared and fully characterized. The Y-shaped structure was confirmed by the single crystal X-ray diffraction technique. The chromophores show interesting second-order nonlinear optical (NLO) properties in solution, as determined by the Electric-Field Induced Second Harmonic generation (EFISH) technique. Remarkably, the trifluro substituted compound 3 is characterized by a high µβEFISH value and has a good potential as molecular building block for composite films with Second Harmonic Generation (SHG) properties. For all compounds, the dipole moments and frontier orbital energies were calculated with Density Functional Theoretical method.