Design and construction of a thermotropic liquid crystal material based on high-nuclear transition-metal cluster-containing polyoxometalates

Abstract

Dimethyldioctadecylammonium (DODA⁺) was used as a surfactant to react with the high-nuclear transition-metal cluster-containing polyoxometalate K₅Na₁₁[Ni₉(OH)₃(H₂O)₆(HPO₄)₂(PW₉O₃₄)₃]·52H₂O (POM-1), resulting in an organic–inorganic hybrid complex (DODA)₁₆[Ni₉(OH)₃(H₂O)₆(HPO₄)₂(PW₉O₃₄)₃]·36H₂O (SEP-1), which exhibits characteristic thermotropic liquid crystalline behavior. Here, the high-nuclear transition-metal cluster-substituted polyoxoanions were firstly introduced into liquid crystalline materials. The chemical composition of the obtained SEP-1 was determined by IR spectra, elemental analysis, and thermogravimetric (TG) analysis. Also, polarized optical microscopy, differential scanning calorimetry (DSC), and variable temperature X-ray diffraction (VT-XRD) were performed on SEP-1 to confirm its thermotropic liquid crystalline behavior.