Host-guest complexation. 35. Spherands, the first completely preorganized ligand systems
作者:Donald J. Cram、Takahiro Kaneda、Roger C. Helgeson、S. Bruce Brown、Carolyn B. Knobler、Emily Maverick、Kenneth N. Trueblood
DOI:10.1021/ja00298a040
日期:1985.6
k2Cs2 = (~~~IU,/KSH+)~~C S~CH+C~,~~,+~,) Abstract: Spherands 1-5 and the related macrocycle 6 which are described in this paper are composed mainly of four to six aryloxy units attached to one another in such a way that the orbitals of the unshared electron pairs of their oxygens line an enforced cavity. These ligand systems strongly complex only Li+ and Na+ ions and reject K', Ca2+, and Mg2+ ions
k2Cs2 = (~~~IU,/KSH+)~~CS~CH+C~,~~,+~,) 摘要:本文描述的球面1-5和相关的大环6主要由四个到六个芳氧基单元彼此连接,使得它们氧的未共享电子对的轨道排列成一个强制空腔。这些配体系统仅强络合 Li+ 和 Na+ 离子并排斥 K'、Ca2+ 和 Mg2+ 离子。报告了它们的合成、代表性晶体结构和对其结合特性的定性调查。这些 18 元环系统的关键闭环涉及在回流苯或 THF 中将适当的双芳基锂与 Fe(acac)3 氧化成芳基,芳基彼此偶联——这是为构建这些主体而发明的反应。1 的晶体结构清楚地显示了其内衬电子对的空腔。l-LiCl 和 l.NaCH3SO4 的晶体结构表明,络合中不涉及宿主的构象重组。多环主体 4.LiFeCl4 和 5.LiCl 复合物的晶体结构显示结扎系统高度紧张并包含严重的氧-氧压缩。