Ultrafast light-driven nanomotors based on an acridane stator

Area of Science:

• Molecular machines
• Supramolecular chemistry
• Organic chemistry

Background:

• Molecular motors are crucial for nanoscale applications.
• Acridane-based structures offer unique properties for motor design.
• Controlling molecular motion requires precise structural engineering.

Purpose of the Study:

• To design and synthesize novel molecular motors utilizing a symmetrical acridane stator.
• To investigate the effect of different rotor units on the performance of molecular motors.
• To characterize the rotational dynamics and operational frequencies of these motors.

Main Methods:

• Synthesis of acridane-based molecular motors with thiopyran and cyclopentanylidene rotors.
• Photochemical and thermal isomerization experiments to study molecular motion.
• Nanosecond transient absorption spectroscopy to monitor thermal processes.

Main Results:

• The acridane stator with a thiopyran rotor exhibited slow thermal helix inversion above 373 K.
• Introducing a cyclopentanylidene rotor significantly decreased steric hindrance, increasing inversion rates by 10^12-fold.
• Molecular motors demonstrated operational frequencies of 0.5 MHz at ambient temperature.

Conclusions:

• Structural modifications of rotor units are key to enhancing molecular motor speed.
• Acridane-based molecular motors show promise for high-frequency applications.
• The developed motors operate efficiently at ambient temperatures.