Structure of Uranium(V) Methyl and Uranium(IV) Ylide Complexes

Rungthanaphatsophon, Pokpong and Stanistreet-Welsh, Kurtis and Ward, Robert J. and Kelley, Steven P. and Lukens, Wayne W. and Kerridge, Andrew and Walensky, Justin R. (2023) Structure of Uranium(V) Methyl and Uranium(IV) Ylide Complexes. Organometallics, 42 (12). pp. 1404-1410. ISSN 0276-7333

Text (U_V_Methyl)
U_V_Methyl.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (734kB)

Abstract

Syntheses of rare examples of U(V) methyl and U(IV) ylide complexes are reported. Reaction of the previously reported U(IV) imido complex [(C 5Me 5) 2U(py)(═NMes)] (py = pyridine, and Mes = 2,4,6-Me 3C 6H 2) with CuI forms the U(V) complex [(C 5Me 5) 2U(I)(═NMes)]. Reaction of the iodo complex with MgMe 2 produces the methyl complex [(C 5Me 5) 2U(CH 3)(═NMes)]. The methyl complex was reacted with CH 2PPh 3, surprisingly forming [(C 5Me 5) 2U(CH 2PPh 3)(═NMes)], a U(IV) ylide. This is formed from a disproportionation of a transient U(V) carbene, leading to the U(IV) ylide and a U(VI) bis(imido) complex, [(C 5Me 5) 2U(═NMes) 2]. These complexes were characterized using spectroscopic methods (nuclear magnetic resonance, infrared, and ultraviolet-visible-nean infrared), SQUID magnetometry, and X-ray crystallography, and density functional theory calculations are used to compare the U(V) methyl with the targeted U(V) carbene ligands.