Gated electron sharing within dynamic naphthalene diimide-based oligorotaxanes

Area of Science:

• Organic electronics
• Supramolecular chemistry
• Charge transport

Background:

• Controlled self-assembly of π-systems is key for organic electronics.
• Investigating stepwise charge transport across noncovalently linked components is a major goal.
• Dynamic oligorotaxanes offer a scaffold for ordered, one-dimensional assemblies.

Purpose of the Study:

• To construct and investigate dynamic oligorotaxanes with varying numbers of naphthalene diimide (NDI) units.
• To explore through-space electronic communication between NDI units via π-orbital interactions.
• To understand how molecular motion influences charge transport in these assemblies.

Main Methods:

• Template-directed synthesis of dynamic oligorotaxanes.
• Incorporation of one to four redox-active NDI units.
• Electrochemical analysis using cyclic voltammetry.
• Electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) spectroscopies.

Main Results:

• Demonstrated electron sharing across NDI stacks within the oligorotaxanes.
• Confirmed electronic communication through π-orbital interactions.
• Observed that thermally driven motions modulate electron passage through NDI stacks.

Conclusions:

• Dynamic oligorotaxanes provide a platform for studying stepwise charge transport.
• The observed charge transfer mechanism is analogous to conformationally gated transfer in DNA.
• These findings advance the design of materials for organic electronic devices.