In this study, a novel series of chiral 1,2-propanediol derivatives with different terminal alkyl chain length were synthesized and characterized by FT-IR, ^1H NMR and DSC. After doped into a nematic liquid crystal ho...In this study, a novel series of chiral 1,2-propanediol derivatives with different terminal alkyl chain length were synthesized and characterized by FT-IR, ^1H NMR and DSC. After doped into a nematic liquid crystal host, all the chiral dopants induced chiral nematic liquid crystals exhibiting a helix inversion with temperature variation. The results indicate that terminal alkyl chain length has a prominent influence on helical twisting property of the chiral dopants. With increasing the terminal alkyl chain length, the molecular twisting power increases, the helix inversion temperatures varies slightly while the phase transition temperature decreases. An odd-even effect may exist in the molecular twisting power of the chirai dopants.展开更多
Two new acetylated kaempferol glycosides were isolated from the seeds of Camellia semiserrata Chi, their structures were elucidated as kaempferol-3-O-[（3-O-acetyl）-a-L-rhamnopyranosyl（1 →3）（4-O-acetyl）-α-L-rha...Two new acetylated kaempferol glycosides were isolated from the seeds of Camellia semiserrata Chi, their structures were elucidated as kaempferol-3-O-[（3-O-acetyl）-a-L-rhamnopyranosyl（1 →3）（4-O-acetyl）-α-L-rhamnopyranosyl（1→ 6）-β-D-glucopyranoside] （1） and kaempferol-3-O-[（2-O-acetyl）-α-L-rhamnopyranosyl （1 →3）（4-O-acetyl）-α-L-rhamnopyranosyl（1 →6）-β-D- gluco-pyranoside] （2） by spectral experiments （including ESI-MS, 1D- and 2D-NMR）..展开更多
基金supported by the National Natural Science Foundation(No.20674005)the Flat-Panel Display Special Project of China 863 Plan(No.2008AA03A318)+1 种基金Projects of Chinese National Science and Technology Tackling Key Problems(No.2007BAE31B02)Program of National Laboratory of Electro-Optics System Technology(No.9140C150102090C1501).
文摘In this study, a novel series of chiral 1,2-propanediol derivatives with different terminal alkyl chain length were synthesized and characterized by FT-IR, ^1H NMR and DSC. After doped into a nematic liquid crystal host, all the chiral dopants induced chiral nematic liquid crystals exhibiting a helix inversion with temperature variation. The results indicate that terminal alkyl chain length has a prominent influence on helical twisting property of the chiral dopants. With increasing the terminal alkyl chain length, the molecular twisting power increases, the helix inversion temperatures varies slightly while the phase transition temperature decreases. An odd-even effect may exist in the molecular twisting power of the chirai dopants.
基金financially supported by the National Natural Science Foundation of China(No.30772714)
文摘Two new acetylated kaempferol glycosides were isolated from the seeds of Camellia semiserrata Chi, their structures were elucidated as kaempferol-3-O-[（3-O-acetyl）-a-L-rhamnopyranosyl（1 →3）（4-O-acetyl）-α-L-rhamnopyranosyl（1→ 6）-β-D-glucopyranoside] （1） and kaempferol-3-O-[（2-O-acetyl）-α-L-rhamnopyranosyl （1 →3）（4-O-acetyl）-α-L-rhamnopyranosyl（1 →6）-β-D- gluco-pyranoside] （2） by spectral experiments （including ESI-MS, 1D- and 2D-NMR）..
