Influence of Lewis Bases on Mesogenic and Luminescent Properties of Eu(III) tris(β-diketonates) Adducts Homogenous Films

A new series of neutral proto-mesogenic EuIII tris(β-diketonate) adducts with different Lewis bases has been synthesized. Only one of the complexes is liquid crystalline, displaying smectic A and nematic mesomorphism over a broad temperature range. Quantum chemistry and small-angle X-ray scattering methods have permitted to evaluate the influence of the Lewis base structure on the anisometry of EuIII adducts molecules and on their subsequent supramolecular organization. The structural features of the presented compounds allow to create vitrified optically isotropic and self-organized films with effective red luminescence. The luminescence spectra of aligned thin films of liquid crystalline EuIII complex are also described.