Selective pathway dynamics of transient helical inversion in supramolecular polymers under non-equilibrium conditions

Abstract Designing the organization of supramolecular systems with high-precision self-assembly along diverse pathways is a crucial strategy for optimizing functional properties. However, attaining this degree of control remains a significant challenge in the field. Here, we report the selective pathway dynamics of platinum (II) terpyridine-based complexes with (R) -chiral side chains, which exhibit three distinct states (Agg-A, -DH, and -SH) in different pathways during the self-assembly process. Specifically, the Pt-complexes ( R )-1 self-assemble into helical structures with opposite handedness as metastable Agg-A (M-type or P-type) depending on concentrations, which led to selective pathways due to transient helical inversion of Agg-A. Our kinetic experiments clearly demonstrated time- and temperature-dependent pathway dynamics. The kinetic observations at 308 K reveal the presence of a kinetically trapped aggregation (Agg-DH) with a double helix driven by interfiber interaction that forms via a transient helical inversion of metastable state (Agg-A) as an on-pathway intermediate (P-type). At 333 K, a thermodynamically favored aggregation (Agg-SH) with a single helix emerges from the metastable state Agg-A as an off-pathway intermediate. Interestingly, the metastable Agg-A can follow two different pathways depending on temperatures, leading to either Agg-DH or Agg-SH. Eventually, both distinct metastable state (Agg-A) and kinetically trapped state (Agg-DH) transform into thermodynamically stable state (Agg-SH). Furthermore, seeded-living supramolecular polymerization was conducted to demonstrate selective pathway control. This study demonstrates the control over pathway complexity and their unique morphological evolution driven by transient helical inversion, as well as interfiber and intermolecular Pt-Pt interactions.