Bpytrisalen/Bpytrisaloph: A Triangular Platform That Spatially Arranges Different Multiple Labile Coordination Sites.

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Multimetallic complexes offer unique functionalities like multivalent capture and catalysis.
• Controlling metal proximity and maintaining reactive coordination sites in such complexes is a significant challenge.

Purpose of the Study:

• To design and synthesize novel organic macrocyclic ligands (bpytrisalen and bpytrisaloph) as platforms for spatial arrangement of multiple metal ions.
• To create well-defined homo- and heteronuclear multinuclear complexes with distinct coordination environments.
• To explore the construction of complex architectures, such as double-decker structures, by leveraging orthogonal coordination sites.

Main Methods:

• Synthesis of bpytrisalen and bpytrisaloph macrocyclic ligands.
• Coordination of various metal ions to the designed ligands to form multinuclear complexes.
• Characterization of the resulting complexes, including structural analysis.
• Investigation of coordination site orthogonality through the construction of double-decker structures using ditopic linker ligands.

Main Results:

• Successfully designed and synthesized bpytrisalen and bpytrisaloph ligands.
• Obtained planar homo- and heterohexanuclear complexes with metals precisely arranged.
• Demonstrated inward-pointing labile coordination sites at bpy units and outward-pointing axial sites at salen/saloph units.
• Selectively constructed a double-decker structure, confirming the orthogonality of coordination sites.
• Achieved consistent metal center and coordination site arrays regardless of the metal element.

Conclusions:

• The developed macrocyclic ligands provide a robust platform for constructing sophisticated multinuclear metal complexes.
• The precise control over metal arrangement and coordination site orientation opens avenues for designing functional supramolecular materials.
• The demonstrated orthogonality of coordination sites is crucial for building complex, multi-layered molecular architectures.