Pinpointing mechanochemical bond rupture by embedding the mechanophore into a macrocycle

Area of Science:

• Materials Science
• Polymer Chemistry
• Mechanochemistry

Background:

• Mechanophores are molecules designed to undergo chemical transformations in response to mechanical stress.
• Atomic Force Microscopy (AFM) provides a powerful tool for quantifying and controlling forces at the single-molecule level.
• Previous mechanophore designs often lack precise control over bond-breaking events and subsequent molecular rearrangements.

Purpose of the Study:

• To synthesize and characterize a novel macrocyclic mechanophore system for precise mechanical force studies.
• To investigate the mechanical response and bond-rupture behavior of the designed mechanophore using single-molecule force spectroscopy.
• To validate experimental findings through comparison with theoretical quantum chemical calculations.

Main Methods:

• Synthesis of a macrocycle incorporating a ring-opening mechanophore and an aliphatic

Main Results:

• Successful synthesis of a macrocyclic mechanophore linked to poly(ethylene glycol) spacers.
• Quantitative measurement of length increase upon mechanophore rupture using single-molecule force spectroscopy.
• Experimental data on bond breaking and force application were corroborated by quantum chemical calculations.

Conclusions:

• The developed macrocyclic mechanophore system allows for controlled mechanical bond scission.
• The combination of mechanophore design and force spectroscopy enables precise mechanical characterization of molecular bonds.
• This work provides a foundation for developing advanced mechanochemical materials and sensors.