A novel series of anthraquinone-based discotic liquid crystals with bulky substituents: synthesis and characterization

Citation
V. Prasad et al., A novel series of anthraquinone-based discotic liquid crystals with bulky substituents: synthesis and characterization, LIQ CRYST, 27(8), 2000, pp. 1075-1085
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
LIQUID CRYSTALS
ISSN journal
0267-8292 → ACNP
Volume
27
Issue
8
Year of publication
2000
Pages
1075 - 1085
Database
ISI
SICI code
0267-8292(200008)27:8<1075:ANSOAD>2.0.ZU;2-M
Abstract
A novel series of anthraquinone-based discotic liquid crystals with bulky s ubstituents? namely 1,5-dibenzyloxy-2,3,6,7-tetraalkyloxy-9, has been synth esized starting from gallic acid. This is, to our knowledge, the first exam ple of bulky substitution in a discotic C-2-symmetric molecule forming colu mnar phases. Except for the lowest homologue, all members of this series ar e found to exhibit columnar mesophases; the low temperature mesophase appea rs to be three-dimensionally ordered whereas the high temperature mesophase is hexagonal columnar (Col(h)). We find that the introduction of benzyl su bstituents for alkyl chains (in the 1,5-positions) on the anthraquinone hex aalkoxylates stabilizes the three-dimensionally ordered phase, whereas it d estabilizes the Col(h) phase, compared with the anthraquinone hexaalkoxylat es. Interestingly, the three-dimensionally ordered phase extends down to - 50 degrees C, making these new derivatives suitable for device applications .