Molecular memory with downstream logic processing exemplified by switchable and self-indicating guest capture and...

Area of Science:

• Supramolecular Chemistry
• Molecular Computing
• Chemical Sensors

Background:

• Molecular-logic based computation (MLBC) has advanced with combinational logic gates but lacks integrated sequential operations, especially in chemistry.
• Biological systems offer inspiration for integrating sequential and combinational operations, yet chemical implementations remain scarce.

Purpose of the Study:

• To report a novel chemical system integrating sequential and combinational operations for molecular logic.
• To demonstrate a chemically-driven RS Flip-Flop with self-indicating occupancy states for molecular capture and release.

Main Methods:

• A macrocycle was designed to switch between large and small cavity states via alcohol-ketone redox interconversion.
• Guest molecule capture and release were controlled chemically, exhibiting an all-or-none response.
• Fluorescence quenching via photoinduced electron transfer was used to indicate the macrocycle's occupancy state.

Main Results:

• The redox-switchable macrocycle successfully integrated combinational and sequential logic operations.
• The system demonstrated a chemically-driven RS Flip-Flop, with outputs feeding into an INHIBIT gate.
• Capture-release phenomena in discrete supramolecular assemblies were shown to have a Boolean basis.

Conclusions:

• This work presents a significant advancement in chemical implementations of molecular logic, bridging combinational and sequential operations.
• The developed system offers a new paradigm for chemical information processing and sensing based on guest molecule interactions.
• The findings pave the way for designing more complex molecular machines and computational systems in chemistry.