Thermically and electrochemically induced isomerization of a (bis(ferrocene)-cyclam)copper(II) complex

Area of Science:

• Coordination Chemistry
• Macrocyclic Chemistry
• Organometallic Chemistry

Background:

• Bis(ferrocene)-cyclam macrocycles represent a unique class of ligands with potential applications in catalysis and materials science.
• Understanding the isomeric behavior of metal complexes with these macrocycles is crucial for controlling their properties.

Purpose of the Study:

• To synthesize and characterize a new bis(ferrocene)-cyclam macrocycle, denoted L.
• To investigate the formation, characterization, and interconversion of copper(II) complexes with L, focusing on type I and type III isomers.
• To explore the electrochemical and structural properties of these complexes.

Main Methods:

• Synthesis of the bis(ferrocene)-cyclam macrocycle (L).
• Isolation and characterization of LCu(II) complexes using X-ray structure determination and electrochemical studies (UV-vis, cyclic voltammetry).
• Investigation of isomer interconversion under various conditions and electrochemical cycling.

Main Results:

• Successful synthesis of the novel bis(ferrocene)-cyclam macrocycle L.
• Isolation and structural characterization of two LCu(II) isomers: type I and type III.
• Demonstration of interconversion between type I and type III isomers, influenced by solvent and electrochemical potential.
• Identification of type III as the thermodynamically more stable isomer and type I as kinetically favored.
• Characterization of a LNi(II) complex.

Conclusions:

• The new bis(ferrocene)-cyclam macrocycle L forms distinct Cu(II) isomers with unique structural and electrochemical properties.
• The interconversion dynamics between isomers can be controlled electrochemically, highlighting potential for redox-switchable systems.
• The findings contribute to the understanding of isomerism in macrocyclic metal complexes and their potential applications.