Covalent organic frameworks (COFs) are crystalline, porous polymers constructed through reversible bond formation between organic monomers. Their modular nature makes them a powerful platform for designing functional organic materials with precise structural control.

A particularly exciting frontier is the development of multicomponent COFs, where multiple types of monomers—differing in topology, size, and functionality—are integrated into a single framework. In principle, this approach can dramatically expand the structural diversity and functional complexity of COFs. In practice, however, their formation is highly challenging. The polymerization process involves competing pathways, including phase separation and the emergence of "COF solid solutions," making rational design extremely more difficult than idealized structural tessellation. 

Our research focuses on uncovering the fundamental factors that govern the successful formation of multicomponent COFs. Ultimately, this work will enable the creation of complex COFs with precisely tuned structures, properties, and functions, opening new possibilities for advanced applications such as selective sensing and catalysis.

Related publication:
J. Am. Chem. Soc. 2023, 145 (5), 3008–3015. https://doi.org/10.1021/jacs.2c11520.

Electrically conductive metal–organic frameworks (c-MOFs) are a rare class of materials that combine structural order, permanent porosity, and electrical conductivity within a single framework. However, achieving both high porosity and excellent conductivity remains a fundamental challenge, as these properties are often intrinsically competing. 

To address this challenge, we employ fully π-conjugated acetylenic macrocycles to construct 2D metal–organic frameworks. Using this approach, we have achieved surface areas exceeding 1500 m² g⁻¹ alongside estimated carrier mobility as high as 100 cm² V⁻¹ s⁻¹, placing the corresponding material among the highest-performing c-MOFs reported to date.  

Our current efforts focus on the reticular expansion of the above material.  Looking ahead, the vast structural diversity of shape-persistent π-conjugated macrocycles offers considerable opportunities for further exploration. Their modular electronic properties, combined with the potential for post-synthetic modifications such as metalation, significantly broaden the scope of structural and electronic tunability in c-MOFs, particularly for applications that require the simultaneous control of mass transport and charge-carrier conduction. 

Related publication:
J. Am. Chem. Soc. 2025, 147 (35), 31940–31951. https://doi.org/10.1021/jacs.5c09695.

Electrochemical sensing and chemiresistive sensing represent some of the most exciting and accessible frontiers for COFs and MOFs. With their exceptional structural tunability and intrinsic porosity, these materials offer unique platform for designing precisely tailored chemical environments—capable of selectively recognizing and discriminating target analytes with high sensitivity. 

Despite early recognition of this potential and a growing body of research, fundamental questions remain unanswered. In particular, the sensing mechanism of COFs and MOFs, and how their framework structures translate into sensing performance are still not well understood. Moreover, the roles of crystallite morphology and film architecture in governing sensing behavior remain largely unexplored.

We tackle these challenges through a systematic and comprehensive exploration of COF and MOF films. By correlating framework design, crystallite morphology, and film structure characteristics, we aim to uncover the underlying principles that dictate their performance. At the same time, we are developing robust and reproducible methods for fabricating high-quality thin films of microcrystalline COFs and MOFs, enabling reliable and consistent device behavior. Through this integrated approach, we seek to unlock the full potential of COF/MOF-based sensors and pave the way toward next-generation technologies, including advanced artificial olfaction systems. 

Related publication:
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