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

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 E_a 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.