Using oriented external electric fields to manipulate rupture forces of mechanophores

Area of Science:

• Computational Chemistry
• Mechanochemistry
• Materials Science

Background:

• Oriented external electric fields (OEEFs) offer a method to modulate chemical reactions by selectively weakening molecular bonds.
• Mechanochemistry utilizes mechanical force to induce chemical transformations, often involving bond rupture in specialized molecules called mechanophores.

Purpose of the Study:

• To investigate the influence of OEEFs on the mechanical force required for mechanophore activation.
• To determine the relationship between OEEF orientation and the reduction in bond rupture force.
• To explore the synergistic effects of mechanical force and OEEFs on molecular bonds.

Main Methods:

• Density functional theory (DFT) electronic structure calculations were employed to simulate mechanophores under OEEFs.
• Natural bond orbital (NBO) analysis was used to elucidate the electronic interactions between OEEFs, mechanical force, and molecular bonds.
• Computational methods combining OEEF simulation with mechanical force application were developed.

Main Results:

• OEEFs substantially decrease the rupture force of mechanophores, facilitating their activation.
• The magnitude of force reduction is highly dependent on the angle between the OEEF and the applied mechanical force.
• Maximum force reduction does not necessarily occur at perfect alignment of the OEEF and mechanical force vectors.
• Mechanical force amplifies the electronic effects of OEEFs on the scissile bond.

Conclusions:

• OEEFs represent a powerful tool for tuning mechanophore activation thresholds.
• Computational analysis provides an effective platform for studying mechanophores in OEEFs.
• Predicting optimal OEEF configurations can guide future experimental design in mechanochemistry.