The iodide (I/CA) and poly(vinylsulfonate) (PA/CA) of bi8(2-hydroxyethyl)ethyl (6-((4-((4nitrophenyl)azo)phenyI)oxy)hexyl)amnionium were prepared, and their liquid-crystalline behavior was compared. The orientational behavior was characterized by X-ray diffraction and conoscopic observation. I/CA and PA/CA exhibited enantiotropically smectic A phases. The ionic groups play an important role in forming the smectic layer structure and enhance the thermal stability of the smectic state. I/CA and PA/CA exhibit an oriented overgrowth on a glass plate by an orientational adsorption of ammonium ion groups. The homeotropic structures form spontaneously in the smectic phase of I/CA and PA/CA and remain unchanged on cooling in the solid phase.
Mesomorphic dimeric compounds consisting of rigid mesogenic cores and flexible oxyethylene chains have been prepared as liquid-crystalline materials capable of complexing with
ionic species. The incorporation of LiCF3SO3 into these materials results in the induction of
smectic A phases and significant mesophase stabilization. The ion−dipole interactions
between lithium ions and oxyethylene moieties have stabilized the mesomorphic layer
structures. Ionic conductivities have been measured for the complexes forming homeotropically aligned molecular orientation of smectic phases. The highest value of conduction,
which is observed for the direction parallel to the layer in the smectic A phase, is 5.5 × 10-4
S cm-1. These results suggest that the complexes of LiCF3SO3 with mesogenic rod−coil−rod molecules containing oxyethylene chains can function as self-organized ion conductive
materials.
The design, structure, and properties of supramolecular
liquid-crystalline side-chain
polymers are described. In particular, we show how several simple
H-bonding building blocks can be
used for the formation of various liquid-crystalline structures.
Poly[4-(6-(acryloyloxy)hexyl- and -undecyloxy)benzoic acid] (PmOBA; m = 6, 11)
have been employed as polymer components. A variety
of
supramolecular mesogenic “copolymers” based on one polymeric
component have been designed and
prepared by simple self-assembly. Cooperation of the hydrogen bond
and electron donor−acceptor
interactions results in the mesophase stabilization for the
“copolymeric” supramolecular structures of
PmOBA with a mixture of
trans-4-methoxy-4‘-stilbazole (1OSz) and
trans-4-cyano-4‘-stilbazole (SzCN)
or trans-4-nitro-4‘-stilbazole (SzNO2).
When a bifunctional molecule, 4,4‘-bipyridine (BPy), is used as
a
component for “copolymeric” structures, supramolecular copolymeric
networks based on PmOBA have
been formed by self-assembly. The networks exhibit stable
mesomorphic behavior and reversible phase
transitions due to the dynamics of the hydrogen bonds.
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