6. (J. Phys. Chem. B) Self-assembled multibilayers of europium alkanoates: Structure, photophysics, and mesomorphic behavior
作者：Haolong Li, Weifeng Bu, Wei Qi, Lixin Wu *
关键字：Europium alkanoates, Liquid crystal
论文来源：期刊
具体来源：The Journal of Physical Chemistry B 2005, 109, 21669-21676.
发表时间：2005年
A series of europium alkanoates (Cn-1H2n-1CO2)3Eu, (n = 14, 16, 18, 20) have been synthesized and characterized in detail. X-ray diffraction and Fourier transform infrared spectroscopic measurements confirm the multibilayer structure of these homologues. In such bilayers, the europium ionic layers are well separated by the highly ordered alkyl chains which are in an all-trans conformation and perpendicular to both sides of the europium ionic layers. There is a mixed-coordination type of chelating bidentate and bridging bidentate between the carboxylate groups and the europium ions. All samples exhibit characteristic emission of europium, though the luminescent intensity has been partly quenched by the carboxylate groups. Differential scanning calorimetry (DSC) shows multiple melting points for these homologues, and temperature-dependent X-ray diffraction measurements also confirm the existence of the mesophase on heating. This mesophase is not truly liquid crystalline, but is similar to the smectic A phase of organic rodlike molecules. Meanwhile, it seems that with increasing atomic number of lanthanide ions, longer alkyl chains will be required to form such a mesophase for the corresponding lanthanide alkanoates.
http://pubs.acs.org/doi/abs/10.1021/jp053980o