Structural and Computational Characterization of a Bridging Zwitterionic-Amidoxime Uranyl Complex

Area of Science:

• Inorganic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Amidoximes are versatile ligands with applications in various chemical fields.
• Uranyl complexes are of interest due to their unique electronic properties and potential applications.

Purpose of the Study:

• To report a previously unobserved bridging binding mode of neutral zwitterionic amidoximes with uranyl.
• To compare this new binding mode with other known uranyl amidoxime complexes.
• To investigate the structural and electronic properties of the resulting dinuclear complex.

Main Methods:

• Synthesis and characterization of uranyl amidoxime complexes.
• Crystallographic analysis to determine the binding mode.
• Density functional theory (DFT) computations to study the potential energy surface.

Main Results:

• A novel bridging (μ2) neutral zwitterionic amidoxime binding mode between amidoximes and uranyl was identified.
• The dinuclear complex exhibits a shallow potential energy surface.
• This shallow surface allows for facile inclusion of a nonbonding water molecule in the solid-state.

Conclusions:

• The discovery of this new binding mode expands the known coordination chemistry of amidoximes with uranyl.
• The structural flexibility indicated by the shallow potential energy surface has implications for the design of new uranyl-based materials.
• The facile inclusion of water molecules suggests potential for applications in host-guest chemistry or sensing.