Synthesis and Reactivity of Terminal U(IV) Hydrides Including the Isolation of a κ<sup>1</sup>-Formate
M. Gayanethra Kaumini, Iker Del Rosal, Pokpong Rungthanaphatsophon, Steven P. Kelley, Laurent Maron, Justin R. Walensky
Abstract
Formation of a rare terminal U(IV) hydride complex, [(C 5 Me 5 ) 2 (2,6- t Bu 2 -4-MeC 6 H 2 O)U(H)], was accomplished through the hydrogenation of a uranium(IV) metallocene hydrocarbyl complex. The reactivity of this hydride was probed with a variety of substrates to examine sigma-bond metathesis, PhEEPh (E = S, Se, Te), and insertion (CO 2, CH 2 ═CH 2 ) reactivity. While the reaction of CO did not produce an isolable result, using the U(IV) hydride with a less sterically encumbering mesityl aryloxide, an ethenediolate is formed, [{(C 5 Me 5 ) 2 (MesO)U} 2 (μ 2 -OC(H)═C(H)O], Mes = mesityl, 2,4,6-Me 3 C 6 H 2 . Each complex has been characterized by NMR, IR, and X-ray crystallographic analysis.