单体
共聚物
圆二色性
高分子化学
热稳定性
溶解度
化学
螺旋(腹足类)
氯仿
对映体
手性(物理)
聚合
比旋转
棉花效应
聚合物
结晶学
物理化学
立体化学
有机化学
生态学
Nambu–Jona Lasinio模型
手征对称破缺
物理
量子力学
蜗牛
生物
夸克
作者
Zhigang Zhang,Jianping Deng,Weiguo Zhao,Jianmin Wang,Wantai Yang
摘要
Abstract A novel chiral N ‐propargylsulfamide monomer ( 1a ) and its enantiomer ( 1b ) were synthesized and polymerized with (nbd)Rh + B − (C 6 H 5 ) 4 as a catalyst providing poly(1) (poly( 1a ) and poly( 1b )) in high yields (≥99%). Poly(1) could take stable helices in less polar solvents (chloroform and THF), demonstrated by strong circular dichroism signals and UV–vis absorption peaks at about 415 nm and the large specific rotations; but in more polar solvents including DMF and DMSO, poly(1) failed to form helix. Quantitative evaluation with anisotropy factor showed that the helical screw sense had a relatively high thermal stability. These results together with the IR spectra measured in solvents showed that hydrogen bonding between the neighboring sulfamide groups is one of the main driving forces for poly(1) to adopt stable helices. In addition, copolymerization of monomer 1a and monomer 2 was conducted, the solubility of poly(1) was improved drastically. However, the copolymerization had adverse effects on the formation of stable helices in the copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 500–508, 2007
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