Three Bis-BODIPY Analogous Diruthenium Redox Series: Characterization and Electronic Structure Analysis

Area of Science:

• Coordination Chemistry
• Organometallic Chemistry
• Supramolecular Chemistry

Background:

• Modified BODIPY ligands offer unique electronic and structural properties for coordination chemistry.
• Ruthenium complexes are versatile in catalysis and materials science due to their tunable redox behavior.

Purpose of the Study:

• To synthesize and characterize novel diruthenium complexes bridged by a dianionic BODIPY-derived ligand.
• To investigate the electronic properties and redox behavior of these multinuclear ruthenium systems.

Main Methods:

• Synthesis of diruthenium complexes featuring a pyrrolo[2,3-f]indole-2,6(1H,5H)-diimine ligand.
• Spectroscopic (EPR, UV-vis-NIR) and structural characterization.
• Electrochemical techniques (cyclic and differential pulse voltammetry).
• Magnetic susceptibility measurements and TD-DFT calculations.

Main Results:

• Successful synthesis of diruthenium complexes with varying ancillary ligands (acac, bpy, pap).
• Characterization of diastereoisomers for one complex (meso and rac forms).
• Demonstration of reversible electron transfer and identification of multiple charge states.
• Assignment of oxidation states revealing diruthenium(III) species and ruthenium(II) species with redox activity at the bridge or ancillary ligands.

Conclusions:

• The dianionic BODIPY-derived ligand effectively bridges two ruthenium centers, forming stable multinuclear complexes.
• The electronic structure and redox properties are highly dependent on the ancillary ligands.
• These complexes serve as platforms for studying electron delocalization and charge transfer in multinuclear metal systems.