| Summary: | 碩士 === 高雄師範大學 === 化學系 === 97 === Three series of liquid crystal compounds were synthesized to study the influence of the structure of terminal group or substituent group on the mesogenic behavior of calamitic liquid crystals or bent-shaped liquid crystals or discotic liquid crystals.The results of liquid crystal properties are summarized as follows：
(1)The compounds of BnOSC3~BnOSC6 all possess smectic A
phase. When the cycloalkyl ring is smaller, the liquid
crystal molecules except BnOSC6 tent to form nematic
phase.They have broader mesogenic temperature range.
(2)The compounds of HOSC3、HOSC4、HOSC5 possess only
nematic phase. The compound HOSC6 can’t exhibit any
mesogenic phase.
(3)The compoumds of the series 2 tend to form mesogenic
phase easily.They have broader mesogenic temperature
range.The compound BMeC3 possess B6 phase, while the
compounds BMeC5 and BMeC6 don’t exhibit any mesogenic
phase. The mesogenic phase of BMeC4 can’t be identified
due to very narrow phase temperature range.
(4)Both the compounds BMeC3 and BMenC4 possess the stable
mesogenic phase. The compound BMnC4 has an
interdigitating structure of smectic phase. The type of
smectic phases is still unknown.
(5)The compounds of OrthoC11, MetaC10, 345C9, 345C10,
345C11 possess Colh phase, but OrthoC10 exhibit Colr
phase. The liquid crystal phase of 345C10 is Colh phase,
not ND phase as punblished in the literature.
|
|---|
