The creation of complex machinery using molecular motors to exploit distinct motion is an ongoing challenge. In particular, designing ways in which a molecular motor can interact intramolecularly with specific components to drive secondary processes and control motion of other parts i.e. coupled rotation, is of significant interest in this area. Here we present a study on the intramolecular interaction of the rotator of a light-powered molecular motor, that is, the part of the molecular motor that rotates as a result of photoexcitation and thermal relaxation, and attached biaryl rotors, being independent rotors that rotate more or less freely. The biaryl rotors are positioned onto the molecular motor in such a way that they sterically interact with the motor and, as a result, are affected by its light-driven rotation. It is shown that in the metastable state, the biaryl rotors show accelerated rotation as a result of a decrease in steric interaction with the motor upper half. Moreover, several new effects were observed that result from varying the size of the biaryl rotors, where they rotate slower or faster depending on whether they are on the naphthalene or methyl side of the motor upper half. • Towards coupled motion, the behavior of rotors on a molecular motor can be controlled by molecular design and photochemical stimuli • In the metastable motor isomer, that was photochemically generated, biaryl rotors rotate faster • The design of the rotors influences both their own rotation frequency and that of the molecular motor
Enk et al. (Fri,) studied this question.