Patterning through controlled submolecular motion: rotaxane-based switches and logic gates that function in solution and polymer films.
Patterning through controlled submolecular motion: rotaxane-based switches and logic gates that function in solution and polymer films.
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DOI：
10.1002/anie.200500101
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发表时间：
2005-05
影响因子：
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通讯作者：
D. Leigh;M. A. Morales;E. Pérez;J. Wong;Carlos G. Saiz;Alexandra M. Z. Slawin;A. Carmichael;
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文献类型：
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作者：
D. Leigh;M. A. Morales;E. Pérez;J. Wong;Carlos G. Saiz;Alexandra M. Z. Slawin;A. Carmichael;
分子机器过程在生物学中的广泛应用[1]激发了人们在功能合成系统中利用类似的良好控制运动的努力。[2]刺激响应的“分子梭”-轮烷三级结构的一个关键特征，互锁组件的相对位置，可以响应外部输入而改变-构成了一种基本的纳米级机械开关，[3]能够改变物理特性，如电导率，[4]圆二色性，[5]和荧光。[6]然而，在聚合物基介质中证明穿梭的例子很少[7]，许多材料应用最终可能依赖于聚合物基介质，并且只有简单的轮烷（不是可切换的分子穿梭）被用于创建信息丰富的四级结构，例如图案化表面。[8]在这里，我们报告了一个系统，其中一个环的移位沿着肽为基础的线程，诱导的性质的变化，当地的环境，可以用来切换荧光的轮烷“开”或“关”。值得注意的是，该系统不仅在溶液中工作，而且在聚合物薄膜中也可以工作，其中肉眼可见的图案可以仅通过受控的亚分子运动来产生。一个聚合物膜“抑制”逻辑门的基础上的组合控制的亚分子定位和化学修饰（质子化）也被证明。线1由连接到甘氨酰甘氨酸氢键结合位点或“站”的蒽荧光团（其也充当“终止子”）组成，所述甘氨酰甘氨酸氢键结合位点或“站”进而连接到可充当第二“疏溶剂”站的C11烷基链[9]并且由第二终止子终止。[10]通过在1的存在下使对苯二甲胺与适当的双（酰氯）缩合，分别以37%和20%的产率制备轮烷2和3（方案1）。[11]3与过量的三氟乙酸的双质子化生成3· 2 H+· 2 CF 3CO 2+。2和3· 2 H+中的大环分别含有硝基苯基和吡啶鎓基团，已知它们通过距离依赖的电子转移猝灭蒽的荧光。[6a从1H NMR光谱中可以清楚地看出，在CDCl 3和[D 6] DMSO（二甲基亚砜）之间，2、3和3· 2 H+· 2 CF 3CO 2的轮烷组分的位置发生了明显的变化。图1示出了在不同的实施方案中，线1和轮烷2的部分1H NMR光谱（400 MHz，298 K）。
The extensive use of molecular machine-like processes in biology [1] is inspiring efforts to exploit similarly well-controlled motions in functional synthetic systems.[2] Stimuliresponsive “molecular shuttles”—rotaxanes in which a key feature of the tertiary structure, the relative positions of the interlocked components, can be changed in response to an external input—constitute a basic kind of nanoscale mechanical switch,[3] capable of varying physical properties such as conductivity,[4] circular dichroism,[5] and fluorescence.[6] However, there are few examples [7] where shuttling has been demonstrated in the polymer-based media upon which many materials applications may ultimately depend, and only simple rotaxanes (not switchable molecular shuttles) have been used to create information-rich quaternary structures, such as patterned surfaces.[8] Here we report a system in which the translocation of a ring along a peptide-based thread, induced by changes in the nature of the local environment, can be used to switch the fluorescence of a rotaxane “on” or “off”. Remarkably, the system not only works in solution but also in polymer films where patterns visible to the naked eye can be generated solely through controlled submolecular motion. A polymer film “INHIBIT” logic gate based on a combination of control of submolecular positioning and chemical modification (protonation) is also demonstrated. Thread 1 consists of an anthracene fluorophore (which also acts as a “stopper”) attached to a glycylglycine hydrogenbonding binding site or “station”, which, in turn, is connected to a C11 alkyl chain that can act as a second “solvophobic” station [9] and is terminated by a second stopper.[10] Rotaxanes 2 and 3 were prepared in 37 and 20% yields, respectively, by condensing p-xylylenediamine with the appropriate bis (acid chlorides) in the presence of 1 (Scheme 1).[11] Double protonation of 3 with an excess of trifluoroacetic acid generated 3· 2 H+· 2 CF3CO2 À. The macrocycles in 2 and 3· 2 H+ contain nitrophenyl and pyridinium moieties, respectively, which are known to quench the fluorescence of anthracene through distance-dependent electron transfer.[6a, 12] A clear change in position of the rotaxane components of 2, 3, and 3· 2 H+· 2 CF3CO2 À between CDCl3 and [D6] DMSO (dimethylsulfoxide) is clearly apparent from 1H NMR spectroscopy. Figure 1 shows the partial 1H NMR spectra (400 MHz, 298 K) of thread 1 and rotaxane 2 in the different