Issue 16, 2019

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. Our findings clearly indicate that the multiple components and phase transitions in crystalline molecular machines can work in concert to achieve the desired motion.

Graphical abstract: Origin of the isotropic motion in crystalline molecular rotors with carbazole stators

Supplementary files

Article information

Article type
Edge Article
Submitted
03 10 2018
Accepted
14 3 2019
First published
20 3 2019
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2019,10, 4422-4429

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

A. Colin-Molina, M. J. Jellen, E. García-Quezada, M. E. Cifuentes-Quintal, F. Murillo, J. Barroso, S. Pérez-Estrada, R. A. Toscano, G. Merino and B. Rodríguez-Molina, Chem. Sci., 2019, 10, 4422 DOI: 10.1039/C8SC04398A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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