CAREER: Mechanochemistry - Breaking Solution-Phase Barriers to Access Challenging Metal-Organic Frameworks

PART 1: NON-TECHNICAL SUMMARY With support from the Solid State and Materials Chemistry Program, this NSF CAREER project explores a new way to create advanced porous materials called metal-organic frameworks (MOFs). These materials are built from metal ions and organic molecules and can store gas, clean water, capture carbon dioxide, and support chemical reactions used in energy technologies. Traditionally, MOFs are made in hot liquid solutions that require high temperatures and large amounts of toxic solvents. These harsh conditions prevent scientists from using many delicate building blocks that could give the materials important new functions. This project uses a different strategy called mechanochemistry, in which chemical reactions are driven by mechanical force, such as grinding or milling, instead of heat and solvents. Working without solvent, also known as working in the solid state, allows reactions to take place quickly at room temperature and opens the door to new structures that cannot be formed using traditional liquid-based methods. The research aims to create new families of MOFs that include sensitive components, show unusual internal structures, or exhibit previously inaccessible properties. The project provides paid research opportunities for undergraduate students, creates a one-credit course focused on sustainable chemistry and scientific career development, and delivers hands-on workshops for K–12 students across Appalachian Ohio. All activities are designed to strengthen STEM workforce development. PART 2: TECHNICAL SUMMARY With support from the Solid State and Materials Chemistry Program, this NSF CAREER project establishes mechanochemistry as a synthetic platform capable of producing metal-organic frameworks (MOFs) that are inaccessible through solvothermal chemistry. The research leverages key features of solid-state reactions, including restricted molecular mobility, solvent-free conditions, and rapid reaction kinetics, to expand the structural and functional landscape of MOFs. Three research directions define the core of the project. First, ambient mechanochemical conditions will be used to incorporate organic and inorganic motifs that degrade under conventional solvothermal conditions, enabling access to fragile or reactive linkers and nodes. Second, the project will exploit solid-state dynamics to favor kinetically preferred products, thereby generating new connectivity regimes, clustered defect architectures, non-equilibrium topologies, and hierarchical porosity. Third, neutron scattering methods will be applied to probe atomistic steps of mechanochemical MOF formation, providing insights into short-range order, amorphous intermediates, and bond rearrangements during milling. Together, these efforts will establish mechanochemistry as a precision-controlled synthetic regime and reveal fundamental principles that govern solid-state reactivity in framework materials. The project provides paid research opportunities for undergraduate students, creates a one-credit course focused on sustainable chemistry and scientific career development, and delivers hands-on workshops for K–12 students across Appalachian Ohio. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.