Structural Elucidation of 1,3-Phenylenebis(methylene)-Bridged Calix[6]arenes with Four Uncapped Hydroxy Groups
Structural Elucidation of 1,3-Phenylenebis(methylene)-Bridged Calix[6]arenes with Four Uncapped Hydroxy Groups
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具有四个未封端羟基的 1,3-亚苯基双（亚甲基）-桥联杯[6]芳烃的结构解析
DOI：
10.1246/bcsj.73.1893
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发表时间：
2000
影响因子：
4
通讯作者：
OkazakiRenji
中科院分区：
文献类型：
--
作者：
SaikiToshiyuki;AkineShigehisa;GotoKei;TokitohNorihiro;KawashimaTakayuki;OkazakiRenji
合成了1，3-亚苯双亚甲基桥联的杯[6]芳烃，其下缘带有四个未封端的羟基，并在桥联单元上具有各种官能团。通过核磁共振谱、分子力学计算和X射线结晶学分析确定了它们在溶液和晶态的结构。他们被发现采用一种夹持的锥形构象，其中桥联的1，3-亚甲基单元位于下面，从而形成锥形的底部。在这些分子中存在着一个很强的分子内氢键网络，形成了一个环状阵列，这个网络被认为在夹持的锥体构象的稳定中起着重要的作用。对桥联单元的构象迁移率也进行了研究。研究发现，中心官能团的空间需求对桥联单元的摆动运动有很大影响。
1,3-Phenylenebis(methylene)-bridged calix[6]arenes with four uncapped hydroxy groups at the lower rim and various kinds of functionalities on the bridging unit were synthesized. Their structures in solution and in the crystalline state were determined by NMR spectroscopy, molecular mechanics calculations, and X-ray crystallographic analyses. They were found to adopt a pinched cone conformation, where the bridging 1,3-phenylenebis(methylene) unit lies below in such a way that it forms the bottom of the cone. There is a strong intramolecular hydrogen bonding network forming a cyclic array in these molecules; this network is considered to play an important role in the stabilization of the pinched cone conformation. The conformational mobility of the bridging unit was also investigated. It was found that the steric demand of the central functionality has a great influence on the swinging motion of the bridging unit.