A Uranium Tri-Rhenium Triple Inverse Sandwich Compound

J Am Chem Soc. 2019 Apr 3;141(13):5144-5148. doi: 10.1021/jacs.9b01331. Epub 2019 Mar 20.

Abstract

Salt metathesis between the anionic rhenium(I) compound, Na[Re(η5-Cp)(BDI)] (BDI = N, N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate), and the uranium(III) salt, UI3(1,4-dioxane)1.5, generated the triple inverse sandwich complex, U[(μ-η55-Cp)Re(BDI)]3, which was isolated and structurally characterized as the Lewis base adducts, (L)U[(μ-η55-Cp)Re(BDI)]3 (1·L, L = THF, 1,4-dioxane, DMAP). The assignment as one uranium(III) and three rhenium(I) centers was supported by X-ray crystallography, NMR and EPR spectroscopies, and computational studies. An unusual shortening of the rhenium-Cp bond distances in 1·L relative to Na[Re(η5-Cp)(BDI)] was observed in the solid-state and reproduced in calculated structures of 1·THF and the anionic fragment, [Re(η5-Cp)(BDI)]-. Calculations suggest that the electropositive uranium center pulls electron density away from the electron-rich rhenium centers, reducing electron-electron repulsions in the rhenium-Cp moieties and thereby strengthening those interactions, while also making uranium-Cp bonding more favorable.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Crystallography, X-Ray
  • Models, Molecular
  • Molecular Conformation
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry
  • Rhenium / chemistry*
  • Uranium / chemistry*

Substances

  • Organometallic Compounds
  • Uranium
  • Rhenium