The diuranium(III) compound [UN′′<inf>2</inf>]<inf>2</inf>(μ-η<sup>6</sup>:η<sup>6</sup>-C<inf>6</inf>H<inf>6</inf>) (N′′=N(SiMe<inf>3</inf>)<inf>2</inf>) has been studied using variable, high-pressure single-crystal X-ray crystallography, and density functional theory . In this compound, the low-coordinate metal cations are coupled through π- and δ-symmetric arene overlap and show close metal-CH contacts with the flexible methyl CH groups of the sterically encumbered amido ligands. The metal-metal separation decreases with increasing pressure, but the most significant structural changes are to the close contacts between ligand CH bonds and the U centers. Although the interatomic distances are suggestive of agostic-type interactions between the U and ligand peripheral CH groups, QTAIM (quantum theory of atoms-in-molecules) computational analysis suggests that there is no such interaction at ambient pressure. However, QTAIM and NBO analyses indicate that the interaction becomes agostic at 3.2 GPa.
- Density functional calculations
- High-pressure chemistry
- X-ray diffraction
ASJC Scopus subject areas