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This study unravels the intricate kinetic and thermodynamic pathways involved in the supramolecular copolymerization of the two chiral dipolar naphthalene monoimide (nmi) building blocks (o-nmi and s-nmi), differing merely by a single heteroatom (oxygen vs sulfur). O-nmi exhibits distinct supramolecular polymerization features as compared to s-nmi in terms of its pathway complexity, hierarchical organization, and chiroptical properties. Two distinct self-assembly pathways in o-nmi occur due to the interplay between the competing dipolar interactions among the nmi chromophores and amide-amide hydrogen (h)-bonding that engenders distinct nanotapes and helical fibers, from its antiparallel and parallel stacking modes, respectively. In contrast, the propensity of s-nmi to form only a stable spherical assembly is ascribed to its much stronger amide-amide h-bonding, which outperforms other competing interactions. Under the thermodynamic route, an equimolar mixture of the two monomers generates a temporally controlled chiral statistical supramolecular copolymer that autocatalytically evolves from an initially formed metastable spherical heterostructure. In contrast, the sequence-controlled addition of the two monomers leads to the kinetically driven hetero-seeded block copolymerization. The ability to trap o-nmi in a metastable state allows its secondary nucleation from the surface of the thermodynamically stable s-nmi spherical “seed”, which leads to the core-multiarmed “star” copolymer with reversibly and temporally controllable length of the growing o-nmi “arms” from the s-nmi “core”. Unlike the one-dimensional self-assembly of o-nmi and its random co-assembly with s-nmi, which are both chiral, unprecedentedly, the preferred helical bias of the nucleating o-nmi fibers is completely inhibited by the absence of stereoregularity of the s-nmi “seed” in the “star” topology. © 2023 american chemical society. |
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