Unidirectional molecular rotary motor with remotely switchable rotation direction

Light-driven rotary motors allow direct transformation of light energy into rotary motion at the nanoscale, giving rise to countless emerging applications in molecular engineering. The key feature enabling the unidirectional rotation and controlling its direction is the motor chirality, a factor hard to modify postsynthetically. Here, we propose a motor architecture, E-motor, whose operation direction can be switched remotely with an electric field pulse, without the need for chemical intervention. Our study relies on quantum chemical calculations and nonadiabatic molecular dynamics simulations performed for a specifically tailored system, PFCN, designed to provide illustration for the proposed motor type. We show that the PFCN chirality depends on the orientation of a covalently bound polar switching unit, which can be controlled with the electric field. At the same time, the proposed system manifests all characteristic photophysical properties of a molecular motor, and its set chirality is preserved during operation in the absence of the field.