Threading in star catenanes: The role of ring rigidity, topology and environmental crowding

Abstract

This study investigates the probability of threading in star catenanes under good solvent conditions using molecular dynamics simulations, emphasizing the influence of ring rigidity. Threading in these systems arises from the interplay between the intrinsic topology of and within the star-shaped structure and the bending rigidity of individual rings. It is demonstrated that reduced ring flexibility enhances threading, and the presence of mechanical bonds is critical for threading formation. Notably, the bending rigidity of the rings alters their shapes, resulting in a non-monotonic threading probability with a peak at intermediate rigidity. Furthermore, increasing ring length is found to significantly boost threading probability. These findings elucidate the intricate relationships among topology and rigidity in governing threading, with implications for the design of advanced molecular systems and materials. This work provides a comprehensive framework for understanding threading in good solvent conditions, where such behavior is typically improbable for ring polymers, and opens avenues for the development of molecular machines and other complex architectures.