Thermo/mechano-mechanically responsive cocrystals during single crystal to single crystal phase transitions

Molecular cocrystals, especially charge-transfer co-crystals, have been found to exhibit distinct optical, electrical and magnetic properties, but they can also show mechanically responsive behaviors under a thermo-, mechano-, or photo-stimulation [1]. However, in this field, understanding structure-property relationships are still lacking. Thus, we utilized a series of in situ techniques (i.e., optical microscope, XRD, AFM and TEM) to observe the thermo-/ mechano-responsive behaviors and single-crystal-to-single-crystal phase transitions in cocrystals and coordination polymers. Some interesting phenomena were found during these experiments, including mechanomechanically responsive oriented single-crystal-to-single-crystal phase transitions in 8-hydroxyquinoline-Based cocrystals (CuQ 2 -TCNQ, and PdQ 2 -TCNQ) [2]; self-healing behavior in thermo-mechanically responsive coronene-TCNB cocrystals