Methyl Scanning for Mechanochemical Chalcogen-Bonding Cascade Switches

Area of Science:

• Chemical biology
• Supramolecular chemistry

Background:

• Chalcogen-bonding cascade switching is a novel method for creating tools to visualize physical forces within biological systems.
• The original flipper probe design featured a methyl group that potentially hindered the cascade switch mechanism.

Purpose of the Study:

• To investigate the role of a specific methyl group in the function of flipper probes.
• To simplify the synthesis of planarizable push-pull probes used for force imaging.

Main Methods:

• Synthesis of demethylated dithienothiophenes with four distinct substituents.
• Comparison of the mechanosensitivity of the original and demethylated flipper probes.

Main Results:

• The deletion of the methyl group in the switching region did not significantly alter the probe's mechanosensitivity.
• Methyl groups in the twisting region were confirmed as essential for probe function.
• The synthesis of the demethylated probe, while complex, validated the findings.

Conclusions:

• Methyl groups in the switching region of flipper probes are not critical for their force-imaging capabilities.
• The chalcogen-bonding cascade switching concept is supported by these findings.
• Simplifying probe structure by removing non-essential methyl groups reduces synthetic complexity for future developments.