Optically Active Homogeneous Mixtures of Cholesteric Liquid Crystals and a New Coordination Compound: Eu(Thenoyltrifluoroacetonate)3. (Cholesteryl Tetradecanoate or Nonanoate)

The reactions of cholesteryl pelargonate (P) or myristate (M) with Eu(thenoyltrifluoroacetonate)3.3H2O (EuTTA3 ) at room temperature give the corresponding complexes Eu(thenoyltrifluoroacetonate)3. (Cholesteryl pelargonate), n H2O (1) and Eu(thenoyltrifluoroacetonate)3. (Cholesteryl myristate), n H2O (2) respectively. When adding these two fluorescent complexes to liquid crystal compounds, optically active and aggregate free mixtures are obtained, containing up to 2.5 molar percent of dopant without loosing the mesogenic properties. The different phases exhibited by these mixtures have been identified. The luminescence properties of these Eu3+ complexes in cholesteric phases have been investigated.