Banerjee Ranit, Chakraborty Debsena, Mukherjee Partha Sarathi
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India.
J Am Chem Soc. 2023 Apr 12;145(14):7692-7711. doi: 10.1021/jacs.3c01084. Epub 2023 Mar 28.
Self-assembled discrete molecular architectures that show selective molecular recognition within their internal cavities are highly desirable. Such hosts often show guest recognition through several noncovalent interactions. This emulates the activity of naturally occurring enzymes and proteins. Research in the formation of 3D cages of different shapes and sizes has progressed rapidly since the development of coordination-driven self-assembly and dynamic covalent chemistry. Such molecular cages find applications in catalysis, stabilization of metastable molecules, purification of isomeric mixtures via selective encapsulation, and even in biomedical applications. Most of these applications stem from the ability of the host cages to bind guests strongly in a selective fashion, providing a suitable environment for the guests to perform their functions. Molecular cages having closed architectures with small windows either show poor encapsulation or inhibit easy guest release while those with wide open structures fail to form stable host-guest complexes. In this context, molecular barrels obtained by dynamic metal-ligand/covalent bond formation techniques possess optimized architectures. With a hollow-walled cavity and two large openings, molecular barrels satisfy the structural requirements for many applications. In this perspective, we will discuss in detail the synthetic strategies for obtaining barrels or barrel-like architectures employing dynamic coordination and covalent interactions, their structure-based classification, and their applications in catalysis, storing transient molecules, separation of chemicals, and photoinduced antibacterial activity. We aim to highlight the structural advantages of molecular barrels over other architectures for efficiently carrying out several functions and for the development of new applications.
在其内部空腔内表现出选择性分子识别的自组装离散分子结构是非常理想的。这类主体通常通过几种非共价相互作用来实现客体识别。这模仿了天然存在的酶和蛋白质的活性。自从配位驱动的自组装和动态共价化学发展以来，关于不同形状和尺寸的三维笼状结构形成的研究进展迅速。这类分子笼在催化、亚稳分子的稳定、通过选择性封装纯化异构体混合物甚至生物医学应用中都有应用。这些应用大多源于主体笼以选择性方式强烈结合客体的能力，为客体执行其功能提供了合适的环境。具有小窗口的封闭结构的分子笼要么表现出较差的封装能力，要么抑制客体的轻易释放，而具有开放结构的分子笼则无法形成稳定的主客体复合物。在此背景下，通过动态金属 - 配体/共价键形成技术获得的分子桶具有优化的结构。分子桶具有中空壁腔和两个大开口，满足了许多应用的结构要求。从这个角度出发，我们将详细讨论采用动态配位和共价相互作用获得桶状或类桶状结构的合成策略、基于结构的分类，以及它们在催化、储存瞬态分子、化学物质分离和光诱导抗菌活性方面的应用。我们旨在突出分子桶相对于其他结构在有效执行多种功能和开发新应用方面的结构优势。
