Heterobimetallic 3d-4f complexes supported by a Schiff-base tripodal ligand

Area of Science:

• Coordination Chemistry
• Inorganic Chemistry
• Materials Science

Background:

• Metal-metal cooperation in heterobimetallic complexes is a key area of research.
• Tuneability of metal centers offers potential for novel applications.

Purpose of the Study:

• Synthesize and characterize heterobimetallic complexes of a 3d metal (Mn, Co) and lanthanum.
• Investigate their electronic structure and metal binding selectivity.

Main Methods:

• Synthesis of heterobimetallic complexes using a tris[(3-methoxysalicylideneamino)methyl]ethane ligand.
• Characterization via electron paramagnetic resonance (EPR) spectroscopy, electrochemical experiments, and computational studies.
• Competitive binding experiments to determine metal site occupancy.

Main Results:

• Selective binding of 3d metal (Mn, Co) to the κ⁶-N₃O₃ site and La to the κ⁶-O₆ site, based on oxophilicity.
• EPR and DFT studies indicate high-spin states for Mn (S=5/2) and Co (S=3/2).
• Electrochemical studies revealed quasi-reversible Mn²⁺/³⁺ redox and irreversible oxidation for Co.

Conclusions:

• The ligand exhibits selective metal binding based on metal oxophilicity.
• The synthesized complexes possess distinct electronic and redox properties.
• These findings contribute to understanding metal cooperation in complex systems.