Surface-Decoupled Altitudinal and Azimuthal Triptycene-Fused Tetrapodal Molecular Motors.

Two light-driven molecular motors, fused to a triptycene-based tetrapodal platform, with rotational axes oriented either parallel or perpendicular to the surface, were successfully designed and synthesized. Both systems demonstrated complete 360° rotation cycles, efficient photoswitching at 385 ± 5 nm (reaching ∼90% at the photostationary state), and quantitative thermal helix inversion with half-lives of ∼7 min at 20 °C. When assembled as monolayers on gold surfaces, the motors retained their full rotational functionality, demonstrating the ability of the tetrapodal platform to minimize surface interactions. These findings highlight the potential of these systems for applications in surface-integrated molecular devices and machines.