Hernandez Raquel, Tseng Hsian-Rong, Wong Jason W, Stoddart J Fraser, Zink Jeffrey I
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
J Am Chem Soc. 2004 Mar 24;126(11):3370-1. doi: 10.1021/ja039424u.
A functioning nanomachine in the form of a supramolecular nanovalve that opens and closes the orifices to molecular-sized pores and releases a small number of molecules on demand is reported. The nanovalve, which is used to open and close the nanocontainer, is a pseudorotaxane composed of two components-a long thread containing a 1,5-dioxnaphthalene donor unit, which is attached to the solid support, and the moving part, the tetracationic cyclophane acceptor/receptor, cyclobis(paraquat-p-phenylene), which controls access to the interior of the nanopore. The nanocontainer is made out of mesoporous silica by using a dip-coating method. Operating the nanovalve involves three steps: (i) filling the container, (ii) closing the valve, and (iii) opening the valve to release the contents of the container on demand. The tubular pores, which are approximately 2 nm wide, are filled with stable luminescent Ir(ppy)3 molecules by allowing them to diffuse into the open pores. The orifices are then closed by pseudorotaxane formation. An external reducing reagent (NaCNBH3) is used to effect dethreading of the pseudorotaxane so as to unlock the tubes and allow the guest molecules to be released. This nanovalve is a supramolecular machine consisting of a solid framework with moving parts capable of doing useful work.
据报道，一种超分子纳米阀形式的功能性纳米机器，它可以打开和关闭通向分子大小孔隙的孔口，并根据需要释放少量分子。用于打开和关闭纳米容器的纳米阀是一种准轮烷，由两个组件组成：一根长链，包含一个连接到固体支持物上的1,5 - 二氧萘供体单元，以及移动部分，即四阳离子环番受体/接受体，环双（百草枯 - 对亚苯基），它控制对纳米孔内部的访问。纳米容器是通过浸涂法由介孔二氧化硅制成的。操作纳米阀涉及三个步骤：（i）填充容器，（ii）关闭阀门，以及（iii）打开阀门以根据需要释放容器中的内容物。大约2纳米宽的管状孔隙通过让稳定的发光铱（ppy）3分子扩散到开放的孔隙中而被填充。然后通过形成准轮烷来关闭孔口。使用外部还原剂（NaCNBH3）来实现准轮烷的解索，从而打开管道并允许客体分子被释放。这种纳米阀是一种超分子机器，由具有能够执行有用工作的移动部件的固体框架组成。
