Complex interactions of pillar[5]arene with paraquats and bis(pyridinium) derivatives
Complex interactions of pillar[5]arene with paraquats and bis(pyridinium) derivatives
复制标题
支柱[5]芳烃与百草枯和双(吡啶鎓)衍生物的复杂相互作用
DOI：
10.1039/b920146g
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发表时间：
2010-01-01
影响因子：
3.2
通讯作者：
Jia, Xueshun
中科院分区：
文献类型：
--
作者：
Li, Chunju;Xu, Qianqian;Jia, Xueshun
采用H-1 NMR、ESI质谱和UV-vis吸收光谱研究了一系列百草枯（G1中心点2 PF（6）-G5中心点2 PF（6））和双吡啶衍生物（G6中心点2 PF（6）-G14中心点2 PF（6））与柱[5]芳烃（P5 A）主体的络合行为。结果表明，P5 A与N，N ′-二烷基-4，4 ′-联吡啶形成2：1的外络合物（G1-G4中心点2 PF（6）），与具有适当链长的亚甲基[-（CH_2）（n）-]联吡啶衍生物形成1：1的准轮烷型包合物（n = 3-6，G7-G10中心点2 PF（6））。在二甲基亚砜（DMSO）中，G7-G10中心点2 PF（6）轴与P5 A轮形成稳定的[2]准轮烷，而1，4-双（吡啶）丁烷（G8中心点2 PF（6））是最合适的轴单元。同时，1，4-双（吡啶）丁烷上取代基的性质也显著影响分子识别行为。吡啶基（G13中心点2 PF（6））的引入不仅增加了K-a值（4.5 × 10（2）-> 7.4 × 10（2）M-1），而且增加了电荷转移（CT）吸收（无色->黄色）。此外，溶剂效应也进行了研究，表明它们显着影响的缔合强度过程中的主-客体络合。特别地，P5 A-G13中心点2 PF（6）在1：1（v：v）丙酮-d（6）/DMSO-d（6）中的K-a值与纯DMSO-d（6）相比提高了7.3倍（7.4 × 10（2）-> 5.4 × 10（3）M-1）。
The complexation behavior of a series of paraquats (G1 center dot 2PF(6)-G5 center dot 2PF(6)) and bis(pyridinium) derivatives (G6 center dot 2PF(6)-G14 center dot 2PF(6)) with pillar[5] arene (P5A) host has been comprehensively investigated by H-1 NMR, ESI mass and UV-vis absorption spectroscopy. It is found that P5A forms 2 : 1 external complexes with N,N'-dialkyl-4,4'-bipyridiniums (G1-G4 center dot 2PF(6)); while it forms 1 : 1 pseudorotaxane-type inclusion complexes with methylene [-(CH2)(n)-] linked bis(pyridinium) derivatives possessing appropriate chain lengths (n = 3-6, G7-G10 center dot 2PF(6)). Host-guest association constants in dimethyl sulfoxide (DMSO) were determined, indicating G7-G10 center dot 2PF(6) axles form stable [2]pseudorotaxanes with P5A wheel in this very high polarity solvent and 1,4-bis(pyridinium) butane (G8 center dot 2PF(6)) was the most suitable axle unit. Meanwhile, the nature of the substituents attached to 1,4-bis(pyridinium) butane dramatically affects the molecular recognition behavior. The introduction of pyridyls (G13 center dot 2PF(6)) increases not only the K-a value (4.5 x 10(2) -> 7.4 x 10(2) M-1), but also the charge transfer (CT) absorption (colorless -> yellow). Furthermore, the solvent effects have also been investigated, showing they significantly influence the association strength during the course of host-guest complexation. Particularly, the K-a value of P5A-G13 center dot 2PF(6) in 1 : 1 (v: v) acetone-d(6)/DMSO-d(6) is enhanced by a factor of 7.3 compared with pure DMSO-d(6) (7.4 x 10(2) -> 5.4 x 10(3) M-1).