Narcissistic Self-Sorting and Enhanced Luminescence via Catenation in Water

Abstract Narcissistic self-sorting, namely that components are able to distinguish “self” from “nonself” during self-assembly, was accomplished via catenation by condensing multiple hydrazides and an aldehyde, or a hydrazide and multiple aldehydes in water. The underneath mechanism of this behavior relies on the corresponding homo [2]catenanes are thermodynamically more favored than their hetero counterparts, because the former containing two identical macrocyclic components are able to maximize the inter-component noncovalent forces. One of these catenanes contains four 4-phenylpyridinium units, which are often considered barely luminescent due to intramolecular rotations and vibrations that lead to nonradiative annihilation of their excited states. These intramolecular motions, however, are restricted upon integrating 4-phenylpyridiniums within the catenane architecture. As a consequence, compared to its non-interlocked counterparts, this catenane exhibits enhanced fluorescence, which represents a novel conceptual model for developing luminescent materials.