Dipartimento di Scienze Chimiche , Università degli Studi di Padova , 35131 Padova , Italy.
J Am Chem Soc. 2019 Jul 31;141(30):11963-11969. doi: 10.1021/jacs.9b04151. Epub 2019 Jul 17.
Nature takes advantage of molecular conformational changes to express functions such as signaling across cellular membranes or allosteric protein activation. At the synthetic level, molecular recognition events have been used to induce conformational changes able to trigger functions such as catalysis or sensing. In this context, transduction of stereochemical information has been the leading strategy. In particular, stereodynamic elements have been extensively employed to amplify and/or transduce chiral information. In this article, we report a chiral supramolecular cage with two stereodynamic units, which invert their helicities according to the length of the molecular guest confined within the system. Interestingly, achiral information is transduced by the supramolecular system to different diastereomeric states that have opposite chiroptical absorptions. This is the first example in which it is possible to produce a continuous modulation of the chiroptical output of a system by varying a physical achiral molecular property (. molecular dimension). This phenomenon can be exploited for the establishment of novel methods to program conformational control, for the development of innovative sensors and/or for transduction of molecular properties into chiroptical information.
自然界利用分子构象变化来表达功能，例如跨细胞膜的信号传递或别构蛋白激活。在合成水平上，分子识别事件已被用于诱导构象变化，从而能够触发催化或传感等功能。在这种情况下，立体化学信息的转换是主要策略。特别是，立体动态元件已被广泛用于放大和/或转换手性信息。在本文中，我们报告了一种具有两个立体动态单元的手性超分子笼，根据系统内受限的分子客体的长度，其螺旋构象会发生反转。有趣的是，手性信息通过超分子体系传递到具有相反旋光吸收的不同非对映异构体状态。这是第一个可以通过改变物理非手性分子性质（分子尺寸）来连续调制体系手性输出的例子。这种现象可用于建立新的方法来编程构象控制，开发创新的传感器和/或将分子性质转换为手性信息。
