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Orientational Self-Sorting in Octahedral Coordination Cages Based on Small, Heteroditopic N-Donor Ligands
Jean de Montmollin1, Cédric Przybylski2, Jean-Yves Salpin2
1Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015Lausanne, Switzerland.
Inorganic Chemistry
|August 10, 2026
Summary
Researchers explored coordination cages using N-donor ligands and palladium (Pd). They formed hexanuclear Pd6L12 cages as isomer mixtures, with attempts to resolve them using cyclic ion mobility-mass spectrometry (cIM-MS).
Area of Science:
- Supramolecular Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Coordination cages are supramolecular structures formed by metal ions and organic ligands.
- Heteroditopic N-donor ligands offer versatile coordination possibilities.
- Isomer formation in coordination cages can impact their properties and applications.
Purpose of the Study:
- To investigate the formation and isomeric diversity of octahedral coordination cages.
- To explore the use of low-symmetry N-donor ligands in cage construction.
- To characterize the resulting cage structures and analyze isomer resolution methods.
Main Methods:
- Synthesis of hexanuclear Pd6L12 cages using N-donor ligands and palladium precursors.
- Characterization using Nuclear Magnetic Resonance (NMR) spectroscopy and single-crystal X-ray crystallography.
- Analysis of isomer mixtures and resolution attempts using cyclic ion mobility-mass spectrometry (cIM-MS).
Main Results:
- Octahedral Pd6L12 cages were successfully synthesized, yielding mixtures of isomers.
- Single-crystal X-ray crystallography confirmed the presence of multiple isomers.
- Kinetically controlled reactions yielded structurally defined Pt2Pd4Cl8L8 cages with specific Pt2+ and PdCl2 coordination.
- Antipodal Pt2+ centers were observed, with ligands exclusively binding to equatorial PdCl2 complexes.
Conclusions:
- Coordination cages constructed from heteroditopic N-donor ligands can exist as diverse isomers.
- NMR spectroscopy and X-ray crystallography are crucial for identifying and characterizing cage isomers.
- Cyclic ion mobility-mass spectrometry (cIM-MS) shows potential for isomer resolution in coordination cages.
- Kinetically controlled synthesis offers a route to specific, structurally defined cage architectures.
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