Layered structures of assembled imine-linked macrocycles and two-dimensional covalent organic frameworks give rise to prolonged exciton lifetimes

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2022-02, Vol.1 (8), p.315-326
• Main Authors: Helweh, Waleed, Flanders, Nathan C, Wang, Shiwei, Phelan, Brian T, Kim, Pyosang, Strauss, Michael J, Li, Rebecca L, Kelley, Matthew S, Kirschner, Matthew S, Edwards, Dillon O, Spencer, Austin P, Schatz, George C, Schaller, Richard D, Dichtel, William R, Chen, Lin X
• Format: Article
• Language: English
• Subjects: Assemblies; Covalence; Depolarization; Diffusion layers; Dipole moments; Dynamic structural analysis; Excitation; Excitons; Internal conversion; Macromolecules; Nanotubes; Optoelectronics; Organic materials
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d1tc05840a

Ordered organic materials and assemblies have great potential to be tailored to have desirable properties for optoelectronic applications, such as long exciton lifetime and high directional exciton mobility. Framework materials, such as two-dimensional covalent organic frameworks (2D COFs), as well as their truncated macrocyclic analogues, are versatile platforms to organize functional aromatic systems into designed assemblies and robust materials. Here we investigate the exciton dynamics in a 2D COF, its corresponding hexagonal macrocycle, and extended nanotubes comprised of stacked macrocycles. The excitonic behavior of these three systems provide an understanding of excitonic processes that occur in the plane of the covalently bonded 2D macromolecules and between layers of the nanotubes and 2D COF. The nanotube and analogous 2D COF exhibit longer excited-state lifetimes (∼100 ps) compared to the individual, solvated macrocycles (