Stimuli-induced folding cascade of a linear oligomeric guest chain programmed through cucurbit[n]uril self-sorting (n=6, 7, 8)
Stimuli-induced folding cascade of a linear oligomeric guest chain programmed through cucurbit[n]uril self-sorting (n=6, 7, 8)
复制标题
DOI：
10.1039/c3sc53211a
复制
发表时间：
2014-01-01
期刊：
影响因子：
8.4
通讯作者：
Schalley, Christoph A.
中科院分区：
文献类型：
--
作者：
Cera, Luca;Schalley, Christoph A.
为了实现由外部刺激驱动的级联转换，我们合成了一个六工位的葫芦b[8]uril和葫芦bb1uril线性来宾。客链是用缺乏电子的紫蛋白和富电子的萘站进行序列编程的，它们由影响链折叠特性的柔性或刚性间隔物连接。再加上两种葫芦素的正交客体选择性，这些性质导致了葫芦素假环紫杉烷折叠物的自分类。每一次转化都由适当的化学和氧化还原输入控制，不仅导致客体链的重新折叠，而且还导致次级信使分子的解放，这使得这里的系统让人想起自然的信号级联。利用紫外/可见光谱、氢-1核磁共振和电喷雾（串联）质谱分析了级联反应的步骤，详细研究了不同假环紫杉烷的结构。一个客体低聚物，三种不同的葫芦烷，几种不同的化学和氧化还原输入，创造了一个化学系统，它表现出超出化学家的纯化合物范式的复杂行为。
A six-station linear guest for cucurbit[7] uril and cucurbit[8] uril has been synthesized in order to implement a cascade of transformations driven by external stimuli. The guest chain is sequence-programmed with electron-deficient viologen and electron-rich naphthalene stations linked by either flexible or rigid spacers that affect the chain's folding properties. Together with the orthogonal guest selectivity of the two cucurbiturils, these properties result in self-sorted cucurbituril pseudorotaxane foldamers. Each transformation is controlled by suitable chemical and redox inputs and leads not only to refolding of the guest chain, but also to the liberation of secondary messenger molecules which render the system presented here reminiscent of natural signaling cascades. The steps of the cascade are analyzed by UV/Vis, H-1 NMR and electrospray (tandem) mass spectrometry to investigate the different pseudorotaxane structures in detail. With one guest oligomer, three different cucurbiturils, and several different chemical and redox inputs, a chemical system is created which exhibits complex behavior beyond the chemist's paradigm of the pure chemical compound.