Examples of using two-dimensional shape-persistent macrocycles, i.e. those having noncollapsible and geometrically well-defined skeletons, for constructing mechanically interlocked molecules are scarce, which contrasts the many applications of these macrocycles in molecular recognition and functional self-assembly. Herein, we report the crucial role played by macrocyclic shape-persistency in enhancing multipoint recognition for the highly efficient template-directed synthesis of rotaxanes. Cyclo[6]aramides, with a near-planar conformation, are found to act as powerful hosts that bind bipyridinium salts with high affinities. This unique recognition module, composed of two macrocyclic molecules with one bipyridinium ion thread through the cavity, is observed both in the solid state and in solution, with unusually high binding constants ranging from ∼10¹³ M⁻² to ∼10¹⁵ M⁻² in acetone. The high efficacy of this recognition motif is embodied by the formation of compact [3]rotaxanes in excellent yields based on either a “click-capping” (91%) or “facile one-pot” (85%) approach, underscoring the great advantage of using H-bonded aromatic amide macrocycles for the highly efficient template-directed synthesis of mechanically interlocked structures. Furthermore, three cyclo[6]aramides bearing different peripheral chains 1–3 demonstrate high specificity in the synthesis of a [3]rotaxane from 1 and 2, and a [2]rotaxane from 3via a “facile one-pot” approach, in each case as the only isolated product. Analysis of the crystal structure of the [3]rotaxane reveals a highly compact binding mode that would be difficult to access using other macrocycles with a flexible backbone. Leveraging this unique recognition motif, resulting from the shape-persistency of these oligoamide macrocycles, in the template-directed synthesis of compact rotaxanes may open up new opportunities for the development of higher order interlocked molecules and artificial molecular machines.

The selective recovery and utilization of Pd(II) from high-level liquid waste (HLLW) is highly desirable for both a flourishing circular economy and the sustainable development of nuclear energy. However, the design of suitable materials is an ongoing challenge due to the complicated composition and extremely radioactive and acidic conditions of HLLW, which requires exceptional selectivity and structural robustness of materials. In this study, two phenanthroline-based covalent organic polymers are constructed through polycondensation of 1,10-phenanthroline-2,9-dicarbaldehyde and 1,3,5-tris-(4-aminophenyl) triazine (COP-1) and subsequent oxidation of imine to amide groups (COP-2). COP-2 demonstrates a high adsorption capacity (318 mg g⁻¹) and outstanding selectivity for Pd(II) over 17 competing cations at 3 M HNO₃ and is stable at high acidity (2–6 M HNO₃) and under a strong radiation field of up to 600 kGy γ irradiation. Additionally, COP-2 is reusable without an obvious decrease in adsorption efficiency after 5 cycles and is feasible for use in the dynamic column separation of Pd(II). More importantly, the Pd(II)-loaded COP-2 obtained from adsorption experiments can be employed as a highly efficient heterogeneous catalyst for Suzuki–Miyaura cross-coupling reactions with excellent reusability for more than 20 successive cycles. This work offers an example of turning wastes into wealth by rationally designing materials for precious metal recovery from HLLW and converting them into valuable catalysts.