Benzobis(imidazolium)-Cucurbit[8]uril Complexes for Binding and Sensing Aromatic Compounds in Aqueous Solution
作者:Frank Biedermann、Urs Rauwald、Monika Cziferszky、Kyle A. Williams、Lauren D. Gann、Bi Y. Guo、Adam R. Urbach、Christopher W. Bielawski、Oren A. Scherman
DOI:10.1002/chem.201002274
日期:2010.12.10
the resulting MBBI⋅CB[8] complex binds to a series of aromatic second guests with Ka values ranging from 103 to 105 M−1. These complexation phenomena were supported by mass spectrometry, which confirmed complex formation, and a series of NMR studies that showed the expected upfield perturbation of aromatic peaks and of the MBBI methyl peaks. Surprisingly, the binding behavior of MBBI is strikingly similar
描述了苯并双(咪唑鎓)盐(BBI)作为涉及大环主体葫芦[8]尿嘧啶(CB [8])的超分子组装体的稳定和荧光组分的用途。CB [8]具有非同寻常的能力,能够紧密选择性地与水性介质中的两个客体结合,通常是作为第一客体的是甲基紫精(MV),然后是包含吲哚,萘或邻苯二酚的第二客体。基于相似的大小,形状和电荷,四甲基苯并双(咪唑鎓)(MBBI)被认为是MV的潜在替代品,它将增加来宾的葫芦库[8] uril。等温滴定热法(ITC)研究表明,MBBI以1:1的比例与CB [8]结合,平衡缔合常数(K a)值为5.7×10 5 M-1,并且所得的MBBI⋅CB[8]络合物以K a值为10 3到10 5 M -1的一系列芳族第二客体结合。这些络合现象得到了质谱的证实,质谱证实了络合物的形成,一系列的NMR研究表明,预期的芳香族峰和MBBI甲基峰的高场扰动。出乎意料的是,MBBI的结合行为与MV非常相似