Metal-centered polyoxometalates encapsulated by surfactant resulting in the thermotropic liquid crystal materials

Waugh-and Silverton-type polyoxometalates (POMs)K-3(NH4)(3)[MnMo9O32] and H-8[CeMo12O42] are enwrapped by dioctadecyldimethylammonium (DODA(+)) forming the surfactant-encapsulated POMs (SEPs) (DODA)6 [MnMo9O32]center dot 16H(2)O (DODA-MnMo9) and (DODA)(8)[CeMo12O42]center dot 9H(2)O (DODA-CeMo12), which exhibit typical thermotropic liquid-crystalline properties. Here, the Waugh-and Silverton-type polyoxoanions centered by metal cation were firstly introduced into liquid crystal materials. The chemical composition of these SEP complexes was determined by IR spectra, elemental analysis and TG analysis. Also, the polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and transmission electron microscopes (TEM) were performed to characterize their liquid-crystalline behavior. (C) 2014 The Authors. Published by Elsevier B.V.