^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-sta...^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-state CP/MAS (cross polarization/magic angle spinning) technique, the spectrum shows that in the crystalline state the ester linkage has a conformation nearly perpendicular to the either side of ring planes, and that the alkoxy groups are not fully in zigzag form. The possible conformational changes around the mesogens from the solid state to the mesophase are discussed.展开更多
The orientational order of two liquid crystals , namely, 6 [4 (4 nitrophenylazo)phenyloxy] hexyl diethanolamines(C6) and 10 1 bromo[4 (nitrophenylazo)phenyloxy] alkane(B10) was studied by means of 2H...The orientational order of two liquid crystals , namely, 6 [4 (4 nitrophenylazo)phenyloxy] hexyl diethanolamines(C6) and 10 1 bromo[4 (nitrophenylazo)phenyloxy] alkane(B10) was studied by means of 2H NMR spectroscopy with hexamethylbenzene d 18 as the probe molecule. The results show that the directors in the smectic A phase of C6 and the nematic phase of B10 could be aligned, which was parallel to the magnetic field. The orientational order parameter of the solute molecules in C6 was about 0.2, while it is only 0.1 in B10, which is expected because the more ordered smectic phase tends to align solute molecules to a high level. Compared to the orientational order parameter of the solute in the SmC phase of 4[3,4,5 tris(4 dodecyloxybenzyloxy) benzoyloxy] 4 (4′ dodecyloxybenzoyloxy)biphenyl (Ⅰ) ( P 2=0.14 ), it is larger in SmA phase of C6. The relatively higher orientational order parameter of the solute in C6 is attributed to the formation of intermolecular H bonds in the SmA phase of C6.展开更多
文摘^(13)C-NMR chemical shifts of model compound of a novel side chain liquid crystalline polymer, poly 2.5-his (4-alkoxybenzoyloxy) styrene , have been assigned in this study. Moreover, by using high-resolution solid-state CP/MAS (cross polarization/magic angle spinning) technique, the spectrum shows that in the crystalline state the ester linkage has a conformation nearly perpendicular to the either side of ring planes, and that the alkoxy groups are not fully in zigzag form. The possible conformational changes around the mesogens from the solid state to the mesophase are discussed.
文摘The orientational order of two liquid crystals , namely, 6 [4 (4 nitrophenylazo)phenyloxy] hexyl diethanolamines(C6) and 10 1 bromo[4 (nitrophenylazo)phenyloxy] alkane(B10) was studied by means of 2H NMR spectroscopy with hexamethylbenzene d 18 as the probe molecule. The results show that the directors in the smectic A phase of C6 and the nematic phase of B10 could be aligned, which was parallel to the magnetic field. The orientational order parameter of the solute molecules in C6 was about 0.2, while it is only 0.1 in B10, which is expected because the more ordered smectic phase tends to align solute molecules to a high level. Compared to the orientational order parameter of the solute in the SmC phase of 4[3,4,5 tris(4 dodecyloxybenzyloxy) benzoyloxy] 4 (4′ dodecyloxybenzoyloxy)biphenyl (Ⅰ) ( P 2=0.14 ), it is larger in SmA phase of C6. The relatively higher orientational order parameter of the solute in C6 is attributed to the formation of intermolecular H bonds in the SmA phase of C6.
