The Force Awakens a Dormant Chemiluminescent Pathway in 1,2-Dioxetane

Area of Science:

• Chemistry
• Materials Science
• Computational Chemistry

Background:

• 1,2-Dioxetanes exhibit chemiluminescence via O-O bond scission, utilized in thermal molecular imaging.
• Mechanochemical triggering of chemiluminescence is key for studying material stress.
• The assumed mechanism for mechanochemical activation mirrors thermal decomposition (O-O scission).

Purpose of the Study:

• To investigate the mechanochemical decomposition pathway of 1,2-dioxetanes using first-principles simulations.
• To determine if applied mechanical force alters the decomposition mechanism.
• To explore the potential for force-induced mechanistic switching in chemiluminescent reactions.

Main Methods:

• First-principles simulations were employed to model the mechanochemically triggered decomposition of 1,2-dioxetanes.
• The study analyzed the energy landscape of decomposition pathways under varying applied forces.
• Simulations considered different pulling directions and chemical substituents, including an adamantyl derivative.

Main Results:

• The traditional O-O scission pathway is largely insensitive to applied force.
• Applied force stabilizes a C-C bond scission pathway, making it energetically favorable above a critical force (1.8-3.0 nN).
• This force-induced mechanistic switch is robust across different conditions and substituents.

Conclusions:

• Mechanical force can fundamentally alter chemical reaction mechanisms, not just accelerate them.
• A new, force-dependent pathway for 1,2-dioxetane chemiluminescence has been identified.
• Findings open avenues for novel mechanophore design and advanced mechanochemical sensing applications.