Enhanced electrooptical active materials based on n-hexyl group flexible isolation in NLO chromophores

Abstract

Two principally novel organic nonlinear optical chromophores (1 and 2) with flexible (n-hexyl group) or rigid isolated (benzyl group) group are designed and successfully synthesized. The prepared chromophores were characterized by MS, 1H-NMR and UV–Vis spectra. Their thermal stability was studied by thermal gravimetric analyzer and differential scanning calorimetry. Poled films of the chromophores doped in amorphous polycarbonate afford the maximum electro-optic tensor coefficient (r33) equal to 39 pm/V, 63 pm/V for chromophore 1 and chromophore 2, respectively at the wavelength 1,064 nm. The reason of so large differences between these two chromophores’ linear electrooptics coefficients were explained within a framework of performed quantum chemical calculations and it is crucially dependent on distances between the chromophore molecules and the polymer chains.