Rate-Acceleration of a Light-Driven Rotary Molecular Motor: Fluorenyl- Based Systems

Exploring the boundaries of a light-driven molecular motor design: new sterically overcrowded alkenes with preferred direction of rotation.

Insight in the steric and electronic parameters governing isomerization processes in artificial molecular motors is essential in order to design more advanced motor systems. A subtle balance of steric parameters and the combination of helical and central chirality are key features of light-driven unidirectional rotary molecular motors constructed so far. In an approach to decrease the steric hi...

Fine tuning of the rotary motion by structural modification in light-driven unidirectional molecular motors.

The introduction of bulky substituents at the stereogenic center of light-driven second-generation molecular motors results in an acceleration of the speed of rotation. This is due to a more strained structure with elongated C=C bonds and a higher energy level of the ground state relative to the transition state for the rate-limiting thermal isomerization step. Understanding the profound influe...

Computational study of the working mechanism and rate acceleration of overcrowded alkene-based light-driven rotary molecular motors

Computational design of faster rotating second-generation light-driven molecular motors by control of steric effects.

We report a systematic computational investigation of the possibility to accelerate the rate-limiting thermal isomerizations of the rotary cycles of synthetic light-driven overcrowded alkene-based molecular motors through modulation of steric interactions. Choosing as a reference system a second-generation motor known to accomplish rotary motion in the MHz regime and using density functional th...

Light-driven rotary molecular motors without point chirality: a minimal design.

A fundamental requirement for achieving photoinduced unidirectional rotary motion about an olefinic bond in a molecular motor is that the potential energy surface of the excited state is asymmetric with respect to clockwise and counterclockwise rotations. In most available light-driven rotary molecular motors, such asymmetry is guaranteed by the presence of a stereocenter. Here, we present non-...