Triggering the dynamics of a carbazole-p-[phenylene-diethynyl]-xylene rotor through a mechanically induced phase transition

Chem Commun (Camb). 2019 Dec 4;55(93):14054-14057. doi: 10.1039/c9cc05672f. Epub 2019 Nov 6.

Abstract

A new rotor exhibits rich solvatomorphism behavior with eight X-ray structures obtained. A heterogeneous solid obtained by mechanical stress exhibited a dominant isotropic 2H line shape at high temperatures. The motion occurs only in the amorphous component of this solid, with an Ea of 7.4 kcal mol-1 and a low pre-exponential factor A of 6.22 × 1010 s-1, which indicates that the motion requires the distortion of the molecular axis.