How does the motion of the surrounding molecules depend on the shape of a folding molecular motor ?

TL;DR

This study investigates how the shape and size of a simplified molecular motor influence surrounding molecule motion, revealing a threshold arm length for effective transport and minimal width dependence.

Contribution

It introduces a simplified rectangular chromophore model to analyze the dependence of photoinduced transport on molecular dimensions, highlighting key shape-related effects.

Findings

Transport increases with chromophore length above a threshold

Minimal dependence of diffusion on chromophore width

Simplified model replicates behavior of real molecular motors

Abstract

Azobenzene based molecules have the property of isomerizing when illuminated. In relation with that photoisomerization property, azobenzene containing materials are the subject of unexplained massive mass transport. In this work we use an idealised rectangular chromophore model to study the dependence of the isomerization induced transport on the chromophore dimensions. Our results show the presence of a motor arm length threshold for induced transport, which corresponds to the host molecule size. Above the threshold, the diffusive motions increase proportionally to the chromophore length. Intriguingly, we find only a very small chromophore width dependence of the induced diffusive motions. Our very simplified motor reproduces relatively well the behavior observed using the real DR1 motor molecule, suggesting that the complex closing procedure and the detailed shape of the motor are not necessary to induce the molecular motions.