Kinetic Control over Pathway Complexity in Supramolecular Polymerization through Modulating the Energy Landscape by Rational Molecular Design

Abstract

Far-from-equilibrium thermodynamic systems that are established as a consequence of coupled equilibria are the origin of the complex behavior of biological systems. Therefore, research in supramolecular chemistry has recently been shifting emphasis from a thermodynamic standpoint to a kinetic one; however, control over the complex kinetic processes is still in its infancy. Herein, we report our attempt to control the time evolution of supramolecular assembly in a process in which the supramolecular assembly transforms from a J-aggregate to an H-aggregate over time. The transformation proceeds through a delicate interplay of these two aggregation pathways. We have succeeded in modulating the energy landscape of the respective aggregates by a rational molecular design. On the basis of this understanding of the energy landscape, programming of the time evolution was achieved through adjusting the balance between the coupled equilibria.

Autocatalytic Time-Dependent Evolution of Metastable Two-Component Supramolecular Assemblies to Self-Sorted or Coassembled State

“…The fact that the t 50 values became longer with increasing the proportion of 2 also excludes the possibility of the cross-catalytic process. Thus, 6 behaves similarly to 1 (and 5 ) in a two-component system with 2 ; in fact, the t 50 values of system (e) were comparable with those of (d) 37 .…”

“…(d) 37 A mixture of 1 and 2 forms a metastable two-component J aggregate, but after a lag time, the system undergoes self-sorting into the H aggregate of 1 and the J aggregate of 2 . An increased proportion of 2 in the mixture impedes H aggregate nucleation of 1 ; this is how the t 50 value for the self-sorting process is determined.…”

Controlling supramolecular polymerization through multicomponent self‐assembly

“…[423][424][425] Sugiyasu, Takeuchi and coworkers have been able to show that seed-induced growth in combination with a competing off-pathway aggregation leads to a "living" supramolecular polymerization of a Zn(II)-porphyrin dye ZnP4 in apolar methylcyclohexan (MCH). 36,426 The competing off-pathway porphyrin J-aggregates with a nanoparticle morphology are formed through isodesmic growth, and act as a kinetic trap that consumes monomers from solution (Fig. 33).…”

Self‐Discriminating Termination of Chiral Supramolecular Polymerization: Tuning the Length of Nanofibers

“…[19] They employed an interplay of isodesmic and cooperative aggregation pathways to achieve living supramolecular polymerization. The present study is the first attempt to control the length of supramolecular fibers in terms of the ee value, or through an interplay of chiral self-recognition and self-discrimination behaviors.…”