title: Investigations on ferroelectric liquid crystal by high resolution TEM and solid state 13C NMR.
abstract: 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 (13)C NMR to record (13)C chemical shifts at different phases. 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 (13)C chemical shifts and line shape vary with different phases. 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.
authors.affiliation: The State Key Laboratory of Electroanalytic Chemistry, Chinese Academy of Sciences, Changchun Institute of Applied Chemistry, Changchun, People's Republic of China.
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Yang
authors.forename: Jingwei
authors.initials: J
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Yunchun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Zijiang
authors.initials: Z
authors.lastname: Jiang
authors.forename: Xin
authors.initials: X
authors.lastname: Ge