Trimetallic Iridium-Nickel-Iridium Bis(formazanate) Assemblies

Area of Science:

• Coordination Chemistry
• Supramolecular Chemistry
• Organometallic Chemistry

Background:

• Formazans, known for their nitrogen-rich conjugated backbone, have been studied in coordination chemistry since the 1940s.
• While formazanates commonly chelate transition metals, their use as building blocks for polynuclear and supramolecular systems is underexplored.

Purpose of the Study:

• To develop a synthetic strategy for novel polynuclear formazanate complexes.
• To explore new binding modes of pyridyl-substituted formazanates.
• To investigate the redox and photophysical properties of heterometallic assemblies.

Main Methods:

• Synthesis of a pyridyl-substituted bis(formazanato)nickel complex acting as a metalloligand.
• Assembly of the nickel complex with two [Ir(C^N)2]+ centers.
• Characterization using cyclic voltammetry and photophysical studies.

Main Results:

• Successful synthesis of trimetallic complexes featuring a novel binding mode for formazanates.
• Demonstration of a new structural class of polynuclear formazanate complexes.
• First-time pairing of 3d (Nickel) and 5d (Iridium) metals within a single formazanate assembly.
• Evaluation of redox properties and confirmation of luminescence originating from the iridium centers.

Conclusions:

• The study expands the scope of polynuclear formazanate chemistry by introducing heterometallic 3d-5d complexes.
• The developed strategy provides a new platform for designing complex supramolecular architectures with tunable properties.
• The luminescent nature of these complexes opens avenues for applications in materials science.