Harnessing the Structural Flexibility of Metal-Organic Frameworks for Novel Functions

Abstract

Metal-Organic Frameworks (MOFs), also known as Porous Coordination Polymers (PCPs), are a class of porous materials based on coordination chemistry, composed of metal ions and polydentate ligands. MOFs are distinguished by their high structural versatility, which can be tailored by adjusting various components such as ligands, metal ions, and synthesis conditions, resulting in highly crystalline structures. Among MOFs, those with flexible frameworks are referred to as "Flexible MOFs." These materials exhibit structural responsiveness to external stimuli, such as the adsorption and desorption of guest molecules, making them particularly intriguing.

By combining structural flexibility with various properties like storage, separation, catalysis, and ion conductivity, Flexible MOFs can be engineered to possess advanced functionalities, including switching capabilities, external field control, and multiple stability states. Our research has primarily focused on exploring the functional potential and elucidating the detailed mechanisms of these dynamic behaviors, especially in the areas of separation, catalysis, and sensor functions.

One notable feature of Flexible MOFs is their selective guest adsorption and separation properties. They exhibit a distinctive adsorption behavior called "gate-opening," characterized by a rapid change in adsorption capacity at pressures exceeding a certain threshold (gate-opening pressure). This gate-opening behavior holds promise for energy-efficient purification processes. We have systematically investigated the structure-property relationships in the adsorption and separation properties of Flexible MOFs and reported some highly unique functionalities. During the presentation, I will focus on our recent research in the development of Flexible PCPs, highlighting their unique adsorption and separation capabilities.

Biography

Ken-ichi Otake completed his Ph.D. in 2016 at Graduate school of Science, Kyoto university, specializing in Chemistry under the guidance of Prof. Hiroshi Kitagawa. Following this, he spent two years as a postdoctoral researcher at Northwestern University, working under the supervision of Prof. Joseph T. Hupp and Prof. Omar K. Farha. In 2018, he became an assistant professor in Prof. Susumu Kitagawa’s group at the Institute for Integrated Cell-Material Sciences at Kyoto University. In 2024, he was promoted to associate professor at the same institute. His research interests include coordination chemistry, solid-state chemistry, and catalysis. He received the 12th SPRUC Young Scientist Award from the SPring-8 users community and the Research Encouragement Award from the Japanese Society of Coordination Chemistry in 2023. 

Google scholar: https://scholar.google.com/citations?user=NvX1TJ4AAAAJ