Resolving the π-assisted U-N σ_f-bond formation using quantum information theory

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Inorganic Chemistry

Background:

• The reaction pathway of UO2(NCO)Cl2- is crucial for understanding uranium compound chemistry.
• Accurate theoretical modeling is needed to elucidate reaction mechanisms and energetics.

Purpose of the Study:

• To model the potential energy profiles of the UO2(NCO)Cl2- reaction pathway.
• To predict relative energies of intermediates and transition states using pair coupled-cluster doubles (pCCD) methods.
• To analyze orbital-pair correlations along the reaction coordinate.

Main Methods:

• Application of different pair coupled-cluster doubles (pCCD) methods.
• Focus on pCCD and pCCD-tailored coupled cluster models.
• Orbital-pair correlation analysis of the reaction pathway.

Main Results:

• Accurate prediction of relative energies for reaction intermediates and transition states.
• Identification of two distinct reaction paths.
• Elucidation of bond formation and breaking mechanisms involving uranium, oxygen, and nitrogen.
• Demonstration of U-N sigma bond strengthening assisted by delocalized pi-type interactions.

Conclusions:

• pCCD methods provide reliable energetics for the UO2(NCO)Cl2- reaction pathway.
• Orbital correlation analysis offers insights into the electronic structure changes during the reaction.
• The U-N bond strengthening is a key feature of the reaction mechanism.