"In order to investigate the structural and dynamical properties of ferroelectric liquid crystal (FLC) in different phases a model compound [4-(3)-(S)-methyl-2-(S)-chloropentanoyloxy)]-4'-nonyloxy-biphenyl (3M2CPNOB) is synthesized. High resolution transmission electron microscopy (HR-TEM) is applied to observe the morphology of 3M2CPNOB and temperature-dependent solid state C-13 NMR to record C-13 chemical shifts at different phases," scientists in Changchun, People's Republic of China report.
"A liquid nitrogen quenching method is used to maintain the conformation of the mesophases for HR-TEM experiments. TEM images show that all the smectic A (SmA), smectic C* (SmC*) and crystalline phases have lamellar morphology. The interplanar distances in the crystalline phase are smaller than those in SmA and SmC* phases because of denser arrangement of the molecules. Both C-13 chemical shifts and line shape vary with different phases," wrote Y.X. Zhao (editor's note: ZHAO Yongxia) and colleagues, Changchun Institute of Applied Chemistry.
The researchers concluded: "The experimental results suggest that SmC* phase as an intermediate occurs in the anisotropy transition process from SmA to crystalline phase, the helical structure of the SmC* phase unwinds in the magnetic field and the conformations of the SmA and isotropic phase are very similar."
Zhao and colleagues published their study in the Journal of Physical Chemistry B (Investigations on Ferroelectric Liquid Crystal by High Resolution TEM and Solid State C-13 NMR. Journal of Physical Chemistry B, 2011; 115(45):13175-13180).
For additional information, contact Y.X. Zhao, Chinese Academy Sci, Changchun Inst Appl Chem, State Key Lab Electroanalyt Chem, Changchun 130022, People's Republic of China. (Source: http://www.verticalnews.com/article.php?articleID=6258434)
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