Origin of the isotropic motion in crystalline molecular rotors with carbazole stators.

ABSTRACT: Herein we report two crystalline molecular rotors 1 and 4 that show extremely narrow signals in deuterium solid-state NMR spectroscopy. Although this line shape is typically associated with fast-moving molecular components, our VT ²H NMR experiments, along with X-ray diffraction analyses and periodic DFT computations show that this spectroscopic feature can also be originated from low-frequency intramolecular rotations of the central phenylene with a cone angle of 54.7° that is attained by the cooperative motion of the entire structure that distorts the molecular axis to rotation. In contrast, two isomeric structures (2 and 3) do not show a noticeable intramolecular rotation, because their crystallographic arrays showed very restricting close contacts

SUBMITTER: Colin-Molina A 

PROVIDER: S-EPMC6482440 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature