A double plug-socket system capable of molecular keypad locks through controllable photooxidation

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photochemistry

Background:

• Multivalent association is crucial for creating complex molecular systems.
• Rigid spacers are often preferred over flexible ones for enhanced binding affinity.
• Controlling molecular interactions and functions is a key challenge in nanotechnology.

Purpose of the Study:

• To construct robust divalent complexes using rigid spacers and specific binding motifs.
• To investigate the role of rigid spacers in achieving strong multivalent association.
• To explore the photoinduced electron transfer (PET) properties and logic functions of these complexes.

Main Methods:

• Synthesis of divalent complexes utilizing anthracene and 1,4,5,8-naphthalenediimide (NDI) as rigid spacers.
• Employing [24]crown-8 ethers and secondary dialkylammonium functionalities as binding motifs.
• Modulating complexation via acid-base reactions to control intermolecular PET.

Main Results:

• Rigid spacers proved more efficient than flexible ones for strong multivalent association.
• Intermolecular PET between spacers could be reversibly switched on/off using acid-base triggers.
• Complexation inhibited photooxidation, demonstrating controllable photochemical behavior.
• Systems exhibited characteristics of molecular keypad locks with alarm functions.

Conclusions:

• Rigid spacers enhance multivalent association through preorganization and charge-transfer interactions.
• The constructed complexes function as a double plug-socket system with switchable electron transfer.
• These systems integrate molecular keypad locks and logic functions into robust multivalent architectures.