Social Self-Sorting Synthesis of Molecular Knots

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Coordination Chemistry

Background:

• Molecular knots are complex topological structures with potential applications in nanotechnology and materials science.
• Controlling the synthesis of specific knot topologies and stereochemistry remains a significant challenge in chemistry.

Purpose of the Study:

• To develop a novel method for the synthesis of molecular prime and composite knots.
• To achieve precise control over knot composition and topological chirality through self-sorting.
• To demonstrate the assembly of trefoil, granny, and square knots with defined stereochemistry.

Main Methods:

• Utilizing social self-sorting of 2,6-pyridinedicarboxamide (pdc) ligands with varying topicity and stereochemistry.
• Employing Lu(III) as a metal template for selective complex formation.
• Applying ring-closing olefin metathesis for covalent capture of the entangled structures.
• Characterizing the synthesized knots using NMR spectroscopy, mass spectrometry, and circular dichroism spectroscopy.

Main Results:

• Selective formation of heteromeric complexes through self-sorting of achiral and chiral pdc ligands.
• Successful synthesis of a single-handed trefoil knot via self-sorting and covalent capture.
• Assembly of heteromeric granny and square knots with controlled stereochemistry by social self-sorting of multi-pdc strands.
• Demonstrated precise control over knot composition and topological chirality.

Conclusions:

• Social self-sorting of pdc ligands provides a powerful strategy for the rational design and synthesis of molecular knots.
• This approach allows for the rapid and selective assembly of complex topological architectures with defined stereochemistry.
• The methodology opens avenues for creating intricate molecular structures for advanced applications.