对称八甲基取代六元瓜环与烷基二氨离子的主客体相互作用

Host-guest Complexation of Octamethyl-substituted Cucurbit6uril with a Series of Alkyldiammonium Ions

摘要: 研究了对称八甲基取代六元瓜环（OMeQ6）/烷基二铵离子（⁺H₃N（CH₂）nNH₃⁺，n=2~8）在溶液中的主客体相互作用。¹H NMR谱图表明，除乙二胺离子外，其余客体分子均与OMeQ6形成了包结物；如果烷基二胺离子的烷基链长度超过5个亚甲基的长度，则烷基链的构象在OMeQ6空腔中被压缩。等温量热滴定（ITC）结果表明，OMeQ6与烷基二胺离子的主客体相互作用的驱动力主要是焓驱动。

Abstract: The host-guest complexation of octamethyl-substituted cucurbit6uril (OMeQ6) with a series of alkyldiammonium ions (⁺H₃N(CH₂)nNH₃⁺,n=2-8) in solution was studied.¹H NMR spectra indicate that all alkyldiammonium ions form inclusion complexes with the OMeQ6,except for the ethanediammonium ion.If the length of the alkyl chain of the alkyldiammonium ion is longer than that of five methylene groups,the alkyl chain is compressed conformation in the cavities of OMeQ6.Isothermal titration calorimetry (ITC) results point out that the host-guest complexation of OMeQ6with the alkyldiammonium ions is mainly driven by enthalpy.