One of the students in the Materials Science and Engineering PhD program will provide an update on their graduate research. Students in the program and students interested in learning more are welcome!

To RSVP, contact Heidi Deethardt for the meeting invitation. deethardt.1@nd.edu.

Presenter

Grace Arntz-Johnson, Department Civil and Environmental Engineering and Earth Sciences

Co-authors

Jennifer Szymanowski, Allen G. Oliver, Peter C. Burns

Title 

Metal-organic frameworks as a platform for the investigation of pentavalent neptunium coordination chemistry

Abstract

Metal-organic frameworks serve as versatile platforms for developing the chemistry of metals spanning the periodic table in addition to their applications. In particular, we explore the coordination modes of neptunium within these frameworks. Np exhibits rich redox and coordination chemistry, that is relatively unexplored due to its radioactivity and limited supplies. A thorough understanding of neptunium chemistry is essential for discernment of the 5f electron contribution to bonding and developing appropriate techniques for nuclear waste stewardship. The prevalence of pentavalent neptunium promotes rare bonding motifs called actinyl-actinyl interactions (AAIs) that result in unique connectivity patterns. We explore the coordination chemistry of neptunium using metal–organic frameworks (MOFs) to understand interactions between neptunium and organic species. Here we report a neptunium MOF structure consisting of anionic neptunyl sheets dominated by AAIs, bridged by 1,4-napthalene dicarboxylic acid and 1,4 benzene dicarboxylic acid. Using X-ray diffraction, Raman spectroscopy, infra-red spectroscopy, and thermal gravimetric analysis, we examine the bonding patterns and properties of the structure gain a better understanding of fundamental Np(V) chemistry.