A Structural and Theoretical Investigation of Equatorial cis and trans
Uranyl Phosphinimine and Uranyl Phosphine Oxide Complexes
UO2Cl2(Cy3PNH)2 and UO2Cl2(Cy3PO)2
posted on 2007-06-11, 00:00authored byL. Jonas L Häller, Nikolas Kaltsoyannis, Mark J. Sarsfield, Iain May, Stéphanie M. Cornet, Michael P. Redmond, Madeleine Helliwell
Phosphinimine ligands (Cy3PNH) readily react with UO2Cl2(THF)3 (THF = tetrahydrofuran) to give UO2Cl2(Cy3PNH)2, which contains strong U−N interactions and exists as cis and trans isomers in the solid and solution state.
Solution NMR experiments and computational analysis both support the trans form as the major isomer in solution,
although the cis isomer becomes more stabilized with an increase in the dielectric constant of the solvent. Mayer
bond orders, energy decomposition analysis, and examination of the molecular orbitals and total electron densities
support a more covalent bonding interaction in the U−NHPCy3 bond compared with the analogous bond of the
related U−OPCy3 compounds.