六元瓜环、对称四甲基六元瓜环与2,2'-(1,8-辛烷)-二异喹啉二溴化物的自组装模式

Supramolecular Assemblies of Cucurbit[6]uril and Symmetrical Tetramethyl-substituted Cucurbit[6]uril with Bromide Salt of2,2'-( Hexane-1,8-diyl) diisoquinolinium

利用核磁共振波谱、紫外吸收光谱、荧光光谱和单晶X射线衍射分析等考察了六元瓜环(Q[6])及对称四甲基六元瓜环(TMeQ[6])与2,2'-(1,8-辛烷)-二异喹啉二溴化物的相互作用.实验结果表明,客体分子分别与这2种瓜环自组装形成相似的1∶1包结配合物,但晶体结构分析结果表明两个体系在主客体分子间作用力诱导下形成了不同的空间堆积模式,其包结常数分别为KK8-Q[6]=4.18×107L/mol,KK8-TMeQ[6]=6.11×107L/mol.

Interactions between cucurbit[6]uril（Q[6]） or symmetrical tetramethyl-substituted cucurbit[6] uril（TMeQ[6]） and bromide salt 2,2’-（hexane-1,8-diyl）diisoquinolinium were studied experimentally by 1 H NMR technology, electronic absorption spectroscopy, fluorescence spectroscopy and single crystal X-ray diffraction method. The experimental results revealed that the interaction of the guest molecule with both Q[6]s respectively could form the similarity inclusion complexes with host/guest ratio of 1：1 in solution state, the binding constants（ K） of the two complexes were in 107 scale. While the crystal structures from two sys-tems showed different supramolecular assemblies due to the geometrical difference from two Q[6]s. The study showed that a 3D framework can be induced by theπ-πstacking of the protruded isoquinolyl moieties. It may provide information in designment of molecular channel, machines and switches.