A Molecular Rotor Driven by an Electric Field on Graphene

Area of Science:

• Molecular Machines
• Nanotechnology
• Computational Chemistry

Background:

• Molecular rotors are essential components in nanoscale devices.
• Controlling molecular rotation with external fields is a key challenge in nanotechnology.

Purpose of the Study:

• To propose and investigate a scheme for continuous rotation of a dipolar molecular rotor using an external electric field.
• To explore the influence of different electric field waveforms on rotor dynamics.

Main Methods:

• Computational modeling combining density functional theory and Newtonian mechanics.
• Simulations mimicking molecular dynamics to calculate torque, angular velocity, and rotation period.
• Machine learning molecular dynamics (MLMD) for thermodynamic stability analysis.

Main Results:

• A dipolar molecular rotor on graphene achieved continuous rotation with a period of 2.96 ps under a specific alternating rectangular electric field (0.5 V/Å).
• Time-dependent cosine wave electric fields were ineffective for regular rotation.
• Angle-dependent cosine wave electric fields successfully drove rotation and generated additional power.
• MLMD simulations confirmed the rotor's thermodynamic stability under electric fields.

Conclusions:

• The study reveals the mechanism of dipolar molecular rotor rotation in a transverse electric field.
• Angle-dependent electric fields offer a promising strategy for driving and powering molecular machines.
• This work provides a foundation for designing diverse molecular machines in experimental settings.