Programming Host–Guest Interactions in Covalent Organic Frameworks with Arylazopyrazole Photoswitches
- 1Department of Chemistry and Biochemistry, California State University, Los Angeles, Los Angeles, California 90032, United States.
- 2Department of Chemistry, Southern Methodist University, Dallas, Texas 75205, United States.
- 3U.S. DOE Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States.
Abstract
Programming host-guest interactions in porous crystalline materials using external stimuli offers a promising strategy for adaptive molecular separations but remains challenging because adsorption is often governed by pore structure rather than tunable molecular interactions. Here, we report a series of photoresponsive covalent organic frameworks (LACOF-1) incorporating arylazopyrazole (AAP) photoswitches that enable light-controlled modulation of CO₂ adsorption through molecular photoisomerization. The framework-embedded AAP units undergo efficient E-Z photoisomerization with an exceptional thermal half-life of ∼76 days while preserving crystallinity and permanent porosity of the framework. Despite exhibiting a lower surface area than the corresponding Z-state, the E-state displays stronger CO₂ adsorption enthalpies, demonstrating that adsorption can be regulated independently of overall pore accessibility. Combined molecular simulations and density functional theory calculations reveal that this behavior arises from enhanced local CO₂ binding within adsorption pockets created by the extended E-AAP configuration. These molecular-level changes translate directly into reversible dynamic CO₂ capture under dry, dilute, and humid conditions, with excellent cycling stability and facile regeneration under ambient conditions. This work establishes molecular photoswitching as an effective strategy for programming adsorption energetics in crystalline porous materials and provides a general design principle for adaptive, stimulus-responsive gas separations.
Related
- Vinylene-Linked Covalent Organic Frameworks with Heteropore-Tuned Compact Motifs for Boosting Spin-Spin Interactions
- Exploring the role of π-π interactions in metallic and covalent organic frameworks based photocatalysis: Design, principles and applications
- Ionic Covalent Organic Frameworks for Solid-State Polymer Electrolytes: Synthesis, Ion-Transport Regulation, and Interfacial Stabilization
- Optimizing the synthesis of imine-linked covalent organic frameworks for high surface areas
- 异孔共价有机框架气相色谱固定相的制备与应用 Preparation and application of heteroporous covalent organic frameworks as gas chromatography stationary phases
BibTeX
@article{yao2026programming,
title = {{Programming Host–Guest Interactions in Covalent Organic Frameworks with Arylazopyrazole Photoswitches}},
author = {Xiyuan Yao and Meng Du and Takeshi Kobayashi and Andres Ruiz and Haoyuan Chen and Long Qi and Yangyang Liu},
journal = {Chemistry of materials : a publication of the American Chemical Society},
year = {2026},
month = oct,
doi = {10.1021/acs.chemmater.6c02293},
url = {https://europepmc.org/article/PMC/PMC13718539},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Programming Host–Guest Interactions in Covalent Organic Frameworks with Arylazopyrazole Photoswitches
AU - Xiyuan Yao
AU - Meng Du
AU - Takeshi Kobayashi
AU - Andres Ruiz
AU - Haoyuan Chen
AU - Long Qi
AU - Yangyang Liu
PY - 2026
DA - 2026/10/05
JO - Chemistry of materials : a publication of the American Chemical Society
DO - 10.1021/acs.chemmater.6c02293
UR - https://europepmc.org/article/PMC/PMC13718539
AB - Programming host-guest interactions in porous crystalline materials using external stimuli offers a promising strategy for adaptive molecular separations but remains challenging because adsorption is often governed by pore structure rather than tunable molecular interactions. Here, we report a series of photoresponsive covalent organic frameworks (LACOF-1) incorporating arylazopyrazole (AAP) photoswitches that enable light-controlled modulation of CO₂ adsorption through molecular photoisomerization. The framework-embedded AAP units undergo efficient E-Z photoisomerization with an exceptional thermal half-life of ∼76 days while preserving crystallinity and permanent porosity of the framework. Despite exhibiting a lower surface area than the corresponding Z-state, the E-state displays stronger CO₂ adsorption enthalpies, demonstrating that adsorption can be regulated independently of overall pore accessibility. Combined molecular simulations and density functional theory calculations reveal that this behavior arises from enhanced local CO₂ binding within adsorption pockets created by the extended E-AAP configuration. These molecular-level changes translate directly into reversible dynamic CO₂ capture under dry, dilute, and humid conditions, with excellent cycling stability and facile regeneration under ambient conditions. This work establishes molecular photoswitching as an effective strategy for programming adsorption energetics in crystalline porous materials and provides a general design principle for adaptive, stimulus-responsive gas separations.
SN - 0897-4756
SN - 1520-5002
ER -