Solid State NMR Studies of Transition Metal Oxides Luis J. Smith, Clark University, DMR 0748399

1. Solid State NMR Studies of Transition Metal OxidesLuis J. Smith, Clark University, DMR 0748399 Layered Phase • This project focuses on the utilization of advanced solid-state NMR methods to examine the local structure of metal atom environments in high surface area niobium oxide materials in order to correlate local structure changes with surface properties at the local level. As the method is element selective, the local niobium environment can be monitored. • Density Functional Theory based quantum mechanical calculations can be used to predict the value of NMR parameters based on a given structure such as the electric field gradient at an atomic site. • Nanosheet versions of perovskite-based Dion-Jacobson niobates have signature electric field gradients values for niobium atoms associated with acid sites as observed via solid state NMR and predicted by DFT methods. The gradient values at protonated nanosheet sites differ significantly (~55 MHz) from the layered version and from niobium atoms unassociated with acid sites on the nanosheet (28 – 30 MHz). Gradient ~ 28 MHz Predicted Gradient ~ 30 MHz ~ 55 MHz Nanosheet Only two Nb sites with distinct gradient values are observed via Nb-93 NMR in the layered form. The nanosheet version is predicted by DFT to have distinct gradient values which result from distinct geometry differences upon protonation. Nb-93 NMR is indicative of presence of the larger gradient in the nanosheet.

2. Solid State NMR Studies of Transition Metal OxidesLuis J. Smith, Clark University, DMR 0748399 • Student outreach to ALANA students and first generation college students via summer institute module on surviving undergraduate science laboratory courses designed by the PI. During the session, students are also introduced to solid state chemistry through microwave heating based ceramic glazing experiment based on the current research of the PI • Undergraduate students (4): • Vanessa Adam • Aaron Dewberry • Yisrael Lattke • Luke Witthoft Incoming ALANA students and first generation college students participating in surviving science laboratory module in solid state chemistry of ACE summer institute at Clark University lead by PI. • Graduate students (3): • Jhashanath Adhikari • Joshua Boykin • Ting Liu