University of Minnesota
University of Minnesota

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DFT and multi-configurational quantum chemical calculations

Recent research from the research group of Professor Laura Gagliardi

The group of L. Gagliardi, University of Minnesota ( and W. Evans, University of California Irvine ( ), performed DFT and multi-configurational quantum chemical calculations to investigate the geometry and electronic structure of several recently synthesized polymetallic uranium nitride and azide complexes [(C5Me5)U(µ-I)2]3N, 1, [(C5Me5)U(µ-I)2]3O, 2, [(C5Me5)2U(µ-N)U(µ-N3)(C5Me5)2]4, 3, [(C5Me5)2UN3(µ-N3)]3, 4, [(C6F5)3BNU(N[Me]Ph)3], 5 and [(C5Me5)U(µ3-E)]8, 6.

(J. Am. Chem. Soc. ASAP

Comparison of 1 and 2 showed that differentiation of U – N vs U – O bond distances is possible. This was accomplished not only in the case of symmetrical 1, which contained three U(IV) centers, but also in the mixed valent 2, where one U(III) and two U(IV) centers were present. This study provided a theoretical proof that the complex with nitrogen is a uranium (IV) nitride, whereas its oxygen analog is a mixed-valence uranium oxide.

The capacity to theoretically predict heavy metal - main group element bond distances is very valuable since complexes exist in which the experimental X-ray data cannot differentiate main group components like N from O in the presence of one or more metals as large as uranium.

The structure of 3