A trefoil knot self-templated through imination in water

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Template-assisted synthesis is common for complex molecular architectures.
• Topologically nontrivial molecules, like knots, present synthetic challenges.
• Imine condensation is typically performed in organic solvents.

Purpose of the Study:

• To develop a template-free method for self-assembling topologically nontrivial molecules.
• To investigate the role of water in molecular self-assembly.
• To synthesize a trefoil knot molecule efficiently in an aqueous environment.

Main Methods:

• Direct condensation reaction between a tetraformyl precursor and a chiral diamine.
• Self-assembly in an aqueous medium.
• Characterization of the resulting molecular structure and topological properties.

Main Results:

• Successful self-assembly of a [3+6] trefoil knot molecule in water without templates.
• The handedness of the trefoil knot is controlled by the stereochemistry of the diamine linker.
• Water was found to be essential for trefoil knot formation, with a trivial macrocycle forming in organic solvents.

Conclusions:

• A robust, template-free method for synthesizing trefoil knots in water has been established.
• Multivalent cooperativity of imine bonds enables stable assembly in aqueous media.
• Hydrophobic effects play a crucial role in driving the self-assembly of this trefoil knot in water.