Oriented External Electric Field Controls the Rupture Forces in Mechanophores

Area of Science:

• Organic Chemistry
• Polymer Chemistry
• Physical Chemistry

Background:

• Controlling molecular reactivity under mechanical stress is crucial in chemistry.
• Mechano-lability is typically induced by structural modifications.
• Existing methods focus on altering pulling groups, ring strain, or bond electron density.

Purpose of the Study:

• To investigate the effect of oriented external electric fields (OEEF) on mechanochemical transformations.
• To demonstrate that OEEF can assist in bond cleavage during mechanical pulling.
• To explore the synergy between OEEF and mechanical force for controlling molecular reactivity.

Main Methods:

• Utilizing a diverse set of ring-opening reactions (1(a)-4(a)).
• Applying an oriented external electric field (OEEF) in conjunction with mechanical pulling.
• Measuring the critical force required for bond cleavage (Frup).

Main Results:

• OEEF significantly reduces the critical force (Frup) for bond cleavage when acting in-phase with bond polarity.
• The effect is dependent on structural asymmetry along the target bond.
• Flipping the OEEF direction enhances the rupture force, demonstrating versatility.

Conclusions:

• Oriented external electric fields (OEEF) can be effectively coupled with mechanical force to control mechano-lability.
• Polar ring-opening reactions are amenable to manipulation by OEEF.
• OEEF and mechanical force act synergistically to control bond cleavage.