The Canadian National Crystallographic Committee will be hosting the eighth Dr. Penelope W. Codding Lecture in support of early career crystallographers on Thursday, July 10 at 10 a.m. Pacific time/1 p.m. Eastern time/2:30 p.m. Newfoundland.

Title: Pores, Purpose, and Diffraction: Understanding MOFs from Synthesis to CO₂ Capture

Abstract:

Metal-Organic Frameworks (MOFs) are a class of porous materials made from metal-based nodes and organic linkers. These nodes—ranging from isolated metal cations to clusters or chains—are bridged by Lewis-basic linkers, often featuring imidazolates, pyridines, or carboxylates. Together, they form 3D frameworks with well-defined pores whose size, shape, and functionality can be tailored by modifying the linker and/or node.

The appeal of MOFs lies in their structural diversity and broad utility, from gas storage and separation (e.g., methane, carbon dioxide) to catalysis and sensing. However, their formation mechanisms remain poorly understood. Most MOFs are synthesized under solvothermal conditions in N,N‑dimethylformamide (DMF). Acids such as acetic acid, benzoic acid, hydrochloric acid, and/or fluoroboric acid, are often introduced as ‘modulators’ to aid in the formation or crystal growth of MOFs. These acids are added in considerable excess yet the precise role of these modulators in guiding crystal growth is unclear. While ¹H-NMR spectroscopy can offer insights into the mechanism of MOF formation, its use is limited by cost of deuterated DMF. We’ve addressed this by employing cost-effective ²H NMR via the lock channel to monitor individual deuterated components, offering new mechanistic insight. By using only one deuterated component and leaving the remaining components in their non-deuterated form, we can isolate and monitor one component at a time thereby reducing issues of peak overlap and relative peak intensities. The first part of the seminar will explore this approach.

In the second part, we turn to carbon dioxide separation/capture. While MOFs are promising for capturing carbon dioxide from point and diffuse sources, the structural features that dictate adsorption efficiency—pore size, shape, functionality, and even defects—remain under debate. Using variable temperature and pressure gas adsorption, we examine how structural characteristics affect adsorption enthalpy, enabling the rational design of materials for direct air capture, or materials with tunable performance. Along our journey from synthesis to applications, we find ourselves looking at crystal structures that have novel symmetry, disorder, and pore-bound solvent. These interesting features will be discussed along the way.

Biography:

Michael Katz is an Associate Professor in the Department of Chemistry at Memorial University of Newfoundland. An inorganic and materials chemist, his research focuses on the synthesis, characterization, and application of MOFs for gas-phase remediation. He earned his PhD at Simon Fraser University with Danny Leznoff, studying non-porous coordination polymers. Afterwords, Mike completed a postdoctoral fellowship at Northwestern University under Joseph T. Hupp and Omar K. Farha, working on dye-sensitized solar cells and MOFs for nerve agent degradation.

Date & Time: Thursday, July 10, 2025, at 10 a.m. Pacific time/1 p.m. Eastern time/2:30 p.m. Newfoundland.