NLO-active Y-shaped ferrocene conjugated imidazole chromophores as precursors for SHG polymeric films
Selvam Prabu, Ezhumalai David, Thamodharan Viswanathan, Krishnan Thirumoorthy, Tamas Panda, Claudia Dragonetti, Alessia Colombo, Daniele Marinotto, Stefania Righetto, Dominique Roberto, Nallasamy Palanisami
Abstract
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 trifluoro substituted compound 3 is characterized by a high μβEFISH value and has good potential as a molecular building block for composite films with Second Harmonic Generation (SHG) properties. For all compounds, the dipole moments and frontier orbital energies were calculated by the Density Functional Theoretical method.