1,3,5-tricorannulenylbenzene: stereochemistry, reduction and supramolecular dimerization of a branched oligocorannulene
1,3,5-tricorannulenylbenzene: stereochemistry, reduction and supramolecular dimerization of a branched oligocorannulene
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DOI：
10.1002/poc.2951
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发表时间：
2013-02-01
影响因子：
1.8
通讯作者：
Shenhar, Roy
中科院分区：
文献类型：
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作者：
Eisenberg, David;Quimby, Jennifer M.;Shenhar, Roy
低聚环烯是由几个共价连接的环烯单元组成的聚芳烃。它们的行为源于每个环烯基单位的不同性质以及它们之间的相互作用。本文介绍了一种新型低聚环烯：支链1,3,5-三环苯基苯的合成、立体化学、还原和自组装性质。几个立体动力学元素结合在一起，产生了丰富的立体化学：碗对碗的反转，芳基-芳基单键的旋转，以及分子螺旋桨的残留立体异构。用金属锂还原得到中间的六阴离子，最终产生高电荷的十二阴离子。自扩散核磁共振表明，通过带电聚芳烃堆叠，十二阴离子经历了超分子二聚化，其中两个分子在所有三个接触点连接。二聚化优于枝聚化是由于熵效应。通过变温1H- nmr和7Li-NMR分析，发现该二聚体具有复杂的结构动力学和离子配对动力学。版权所有：John Wiley & Sons， Ltd
Oligocorannulenes are polyarenes composed of several corannulene units that are covalently linked. Their behavior arises both from the diverse properties of each corannulenyl unit and from the interactions between them. In this paper, we present the synthesis, stereochemistry, reduction, and self-assembly properties of a novel type of oligocorannulene: branched 1,3,5-tricorannulenylbenzene. Several stereodynamical elements combine to give rich stereochemistry: bowl-to-bowl inversion, rotation about the aryl-aryl single bonds, and residual stereoisomerism of molecular propellers. Reduction with lithium metal yields an intermediate hexaanion and ultimately produces a highly charged dodecaanion. Self-diffusion NMR demonstrates that the dodecaanion undergoes supramolecular dimerization through charged polyarene stacking, wherein two molecules are linked at all three contact points. The preference for dimerization over dendrimerization is attributed to an entropic effect. The dimer is found to undergo complex structural dynamics, as well as ion-pairing dynamics, as revealed by variable-temperature 1H- and 7Li-NMR. Copyright (C) 2012 John Wiley & Sons, Ltd.