Preparation and crystallinity of a large unsubstituted crown ether, cyclic heptacosa(oxyethylene)(cyclo-E27, 81-crown-27), studied by Raman spectroscopy, X-ray scattering and differential scanning calorimetry
作者:Zhuo Yang、Ga-Er Yu、Jennifer Cooke、Ziad Ali-Adib、Kyriakos Viras、Hiroatsu Matsuura、Anthony J. Ryan、Colin Booth
DOI:10.1039/ft9969203173
日期:——
α-hydro, ω-hydroxy-heptacosa(oxyethylene) by reaction with tosyl chloride under alkaline conditions, purified by preparative-scale gel permeation chromatography, and studied by laser-Raman spectroscopy, wide-angle and small-angle X-ray scattering, and differential scanning calorimetry. Comparison was made with the properties of linear oligo(oxyethylene) dimethyl ethers (including C1E27C1). The sub-cell
环状二十七(oxyethyelene)(环-E 27,81冠27)制备线性α羟基苯,ω -羟基二十七(氧乙烯)通过在碱性条件下对甲苯磺酰氯,由制备级凝胶渗透色谱法纯化反应,并通过激光拉曼光谱,广角和小角X射线散射以及差示扫描量热法进行了研究。与线性低聚(氧乙烯)二甲基醚(包括C 1 E 27 C 1)的性质进行了比较。结晶环状低聚物的子单元与其线性对应物的子单元相同,即与高摩尔质量的聚氧乙烯相同。然而,环状低聚物结晶为两倍折叠的环,这是由其较长的间隔和其单节点纵向声模(LAM-1)的频率所证实的。分析了熔化和熔融温度的焓,以提供在低聚(氧化乙烯)层晶体中形成折叠的焓和熵的估计。