Adaptive and Dynamic Nonintertwined Assembly of Rigid and Flexible Rings
Tao Wang, Xuan He, Jieqiong Xu, Dengke Shen, Liyun Mei, Guoyong Xu, Peifa Wei, Ben Zhong Tang
Abstract
Biomorphic supramolecular assemblies formed through the collaboration of rigid and flexible elements, akin to bones and ligaments, play a crucial role in constructing advanced functional structures. Non-intertwined ring-ring assemblies that rely on induced fitting between rigid rings and conformationally flexible rings have emerged as thriving representatives of this process. However, detailing how rigid and flexible rings adapt to each other for precise self-assembly evolution under solely weak non-covalent interactions remains limited and often poses challenges in structural design. We offer a distinctive solution by distorting the rigid cyclophane, thereby providing not only unique dual recognition sites for flexible guests but also intrinsic solid-state emission for in-situ visualization of dynamic processes. Three adaptive self-assemblies ranging from ring-within-ring, to ring-bridge-ring and finally to ring-in-ring were constructed and demonstrated to be dynamically responsive in the solid state through harnessing the high selectivity of the inner rings.