Induced mesophases in binary mixtures of lanthanide(III) dodecanoates

Mesophase induction was observed in binary mixtures of the liquid-crystalline lanthanum(III) dodecanoate and a nonmesomorphic lanthanide(III) dodecanoate. The compounds have the stoichiometry La(x)Ln(1-x)(C11H23COO)(3) (where x is the mole fraction of lanthanum, Ln = Nd, Eu, Ho, Tb, and Yb) and were characterized by elemental microanalysis. The thermal behavior was investigated by hot-stage polarized optical microscopy, by differential scanning calorimetry, and by X-ray diffraction at elevated temperatures. The mesophase behavior of the compounds strongly depends on the composition of the mixtures and on the lanthanide ion. For lanthanum-europium dodecanoate mixtures, less than 4 mol % lanthanum(III) dodecanoate is needed to induce mesomorphism, whereas for lanthanum-ytterbium mixtures, the minimum amount of lanthanum(III) dodecanoate increases to 48 mol %.