138705-74-5Relevant academic research and scientific papers
Hierarchical superstructures with control of helicity from the self-assembly of chiral bent-core molecules
Lin, Shih-Chieh,Ho, Rong-Ming,Chang, Chin-Yen,Hsu, Chain-Shu
supporting information; experimental part, p. 9091 - 9098 (2012/10/08)
Herein, two asymmetric chiral bent-core molecules, 3-[(4-{[4-(heptyloxy) benzoyl]oxy}benzoyl)oxy]-phenyl-4-[(4-{[(1R)-1-methylheptyl]oxy}benzoyl)oxy] benzoate (BC7R) and 3-[(4-{[4-(heptyloxy)benzoyl]oxy}benzoyl)oxy]-phenyl-4-[(4- {[(1S)-1-methylheptyl]oxy}benzoyl)oxy] benzoate (BC7S), were synthesized to demonstrate control of the helicity of their self-assembled hierarchical superstructures. Mirror-imaged CD spectra showed a split-type Cotton effect after the formation of self-assembled aggregates of BC7R and BC7S, thereby suggesting the formation of intermolecular exciton couplets with opposite optical activities. Both twisted and helical ribbons with preferential helicity that corresponded to the twisting character of the intermolecular exciton couplet were found in the aggregates. The formation of helical ribbons was attributed to the merging of twisted ribbons through an increase in width to improve morphological stability. As a result, control of the helicity of hierarchical superstructures from the self-assembly of bent-core molecules could be achieved by taking advantage of the transfer of chiral information from the molecular level onto the hierarchical scale.
Fluoro- and nitro-substitution effect of some chiral compounds
Guo, Yongmin,Bi, Lifeng,Li, Baozong,Yang, Yonggang,Wen, Jianxun
scheme or table, p. 65 - 70 (2010/04/02)
Four chiral compounds have been synthesized. Their phase transition behavior was investigated by differential scanning calorimetry and polarized optical microscopy. Two of them show monotropic smectic C* phases. Moreover, one of them shows an enantiotropic blue phase. The lateral fluoro-substitution strongly suppressed the formation of SmC* phases and decreased clearing points. Although the introduction of nitro group in the core decreased the length-diameter ratio, the temperature range of monotropic SmC* phase did not change much.
