Leung Ken Cham-Fai, Chak Chun-Pong, Lo Chui-Man, Wong Wing-Yan, Xuan Shouhu, Cheng Christopher H K
Center of Novel Functional Molecules, Department of Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
Chem Asian J. 2009 Mar 2;4(3):364-81. doi: 10.1002/asia.200800320.
This Focus Review surveys representative examples of pH-controllable supramolecular systems with interesting features and state-of-the-art applications such as 1) conformational changes within individual molecules; 2) folding/unfolding of polymers; 3) simultaneous binding of cations and anions; 4) logic function; 5) ON-OFF switchable colorimetric sensing; 6) translocation of macrocycle-in-rotaxane molecules; 7) large-scale movement within molecules; and 8) regulation of the substrate flow in nanocontainers. In particular, systems will be discussed that involve: pH-induced conformational changes of a resorcinarene cavitand and a bis(iron porphyrin) complex; pH control in assembly and disassembly of supramolecular systems stabilized with different major noncovalent interactions; pH-driven movements of interlocked molecules involving rotaxanes, molecular elevators, and molecular muscles; and, finally, multicomponent supramolecular systems immobilized on solid supports as pH-responsive nanovalves for the controlled release of specific substrates. Recent advances in the understanding of pH-controllable supramolecular systems have led to the construction of meaningful molecular machines for electronic and biological applications that are amenable to control by simple perturbation with acids and bases.
本聚焦综述考察了具有有趣特性和前沿应用的pH可控超分子体系的代表性实例，例如：1）单个分子内的构象变化；2）聚合物的折叠/解折叠；3）阳离子和阴离子的同时结合；4）逻辑功能；5）开-关可切换比色传感；6）轮烷中大环分子的移位；7）分子内的大规模运动；以及8）纳米容器中底物流动的调节。特别地，将讨论涉及以下方面的体系：间苯二酚芳烃穴状配体和双（铁卟啉）配合物的pH诱导构象变化；通过不同主要非共价相互作用稳定的超分子体系组装和解组装过程中的pH控制；涉及轮烷、分子电梯和分子肌肉的互锁分子的pH驱动运动；以及最后，固定在固体载体上作为pH响应纳米阀用于特定底物控制释放的多组分超分子体系。对pH可控超分子体系理解的最新进展已促成了用于电子和生物应用的有意义分子机器的构建，这些分子机器可通过简单的酸碱扰动进行控制。
