Arene bridged diuranium compounds supported by amide and ketimide ligands

Chapter 1: The Intriguing Geometric and Electronic Structure of Arene-Bridged Diuranium Tetrakisamido Complexes The focus of this chapter is to characterize and contextualize the bridged arene complex (-toluene)U2(N[t-Bu]Ar)4 (lb2-gl-toluene, Ar = 3,5-C6H3Me2). To do so, lb2-g-toluene is compared extensively with the mononuclear complexes (THF)U(N[1Ad]Ar)3 (2a-THF, THF = tetrahydrofuran), JIU(N[t-Bu]Ar)3 (la-I), IU(N['Ad]Ar)3 (2a-I), and Me3SiNU(N[1Ad]Ar)3 (2a- NSiMe3). In order to understand the properties of a unique compound such as lb2-pg-toluene, the rest of the series is based on classical uranium amide compounds. The syntheses, structures (X-ray crystal structures and solution behavior based on variable temperature, VT, NMR data), spectroscopic (X-ray absorption near-edge structure, XANES, and electronic absorption - UV- vis-NIR) and magnetic properties are discussed and interpreted with reference to results of density functional theory (DFT) calculations performed on model compounds. Reactivity studies of lb2-p-toluene are then presented and analyzed. Chapter 2: Arene Bridged Diuranium Complexes Supported by a Ketimide Ligand: Even and Odd Electron Redox Pairs The ketimide ligand NC[t-Bu]Mes (Mes = 2,4,6-C6H2Me3) employed in the present study allows for retention of three supporting ligands per uranium, giving rise to a three-legged piano stool geometry, and it also allows for incorporation of potassium ions as tight ion pairs. The generality of such a ligand is well supported by the existence of the two types of compounds M2(g-arene)U2(NC[t-Bu]Mes)6 (M2-32-g-arene, M = Na, K) and K-32-pt-arene, when the arene is naphthalene, biphenyl, trans-stilbene, or p-terphenyl.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Diaconescu, Paula L. (Paula Loredana), 1976-

Advisor dc:contributor.advisor

• Christopher C. Cummins.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/29638

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/29638