Guest-Shuttling in a Nanosized Metallobox

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Metallosupramolecular assemblies offer unique structural and functional properties.
• Designing novel architectures with specific binding capabilities is a key challenge.
• Fused polyaromatic systems are of interest for their electronic and photophysical properties.

Purpose of the Study:

• To synthesize and characterize a novel, long, and narrow iridium-conjoined metallorectangle.
• To investigate the binding properties of this metallorectangle with planar organic molecules.
• To explore the dynamic behavior of guest molecules within the metallorectangle cavity.

Main Methods:

• Synthesis of a quinoxalinophenanthrophenazine-connected Janus-di-imidazolylidene ligand.
• Coordination of the ligand with an iridium precursor and pyrazine to form the metallorectangle.
• Spectroscopic and crystallographic analysis to confirm the structure and properties.
• Binding studies with planar organic molecules to assess guest-host interactions.

Main Results:

• A novel iridium-conjoined, slit-like metallorectangle was successfully synthesized.
• The metallorectangle exhibits exceptionally high binding affinities for planar organic molecules.
• Guest molecules are asymmetrically occupied within the cavity, leading to large amplitude motion.
• This dynamic behavior demonstrates the metallorectangle's function as a molecular shuttle.

Conclusions:

• The synthesized iridium metallorectangle possesses unique size, shape, and electronic properties.
• It acts as an effective host for planar organic molecules, enabling asymmetric guest occupation.
• The observed molecular motion highlights its potential as a component in molecular machines and advanced materials.