Thermotropic liquid crystals built from organic–inorganic hybrid polyoxometalates and a simple cationic surfactant

By ion metathesis reactions, the dimethyldioctadecylammonium (DODA+) was used as the surfactant to encapsulate organic–inorganic hybrid polyoxometalates (POMs) (NH4)6{Mo2VO4[(Mo2VIO6)NH3CH2CH2CH2C(O)(PO3)2]2}·10H2O (POM-1) and (NH4)8{Mo2VO4[(Mo2VIO6)CH3C(O)(PO3)2]2}·14H2O (POM-2), resulting in two surfactant-encapsulated clusters (SECs) with characteristic thermotropic liquid-crystalline behavior. The chemical composition of the obtained SECs was determined by IR spectra, elemental analysis, TG analysis and NMR spectra. Also, polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and TEM of the samples were also performed, which revealed that both SECs show thermotropic liquid crystal behavior.