Controlling uranyl oxo group interactions to group 14 elements using polypyrrolic Schiff-base macrocyclic ligands

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Uranium Chemistry

Background:

• Schiff-base macrocyclic ligands are versatile platforms for coordinating metal ions.
• Heterodinuclear complexes involving uranyl and group 14 elements are of interest for their unique electronic and structural properties.

Purpose of the Study:

• To synthesize and characterize heterodinuclear uranyl/group 14 complexes using aryl- and anthracenyl-linked Schiff-base macrocyclic ligands.
• To investigate the influence of ligand structure on metal-metal interactions within these complexes.

Main Methods:

• Synthesis of uranyl/group 14 complexes via reaction of UO2(H2L) with M{N(SiMe3)2}2 (M = Ge, Sn, Pb).
• Structural characterization using X-ray crystallography and IR spectroscopy.

Main Results:

• Complexes with anthracenyl-linked ligands (L^A) showed group 14 metals displaced from the N4-donor plane, with minimal oxo-group 14 metal interaction.
• The aryl-linked ligand (L^Me) facilitated greater interaction, particularly in the lead(II) complex, where uranyl-lead interaction was observed upon coordination of pyridine-N-oxide.

Conclusions:

• Ligand design is crucial in controlling the degree of interaction between uranyl and group 14 metals in heterodinuclear complexes.
• The aryl-linked ligand promotes closer proximity and interaction between the uranyl and lead(II) ions.