High-Temperature Ferroelastic Phase Transition in an Organic–Inorganic Hybrid: [(CH₃)₃NCH₂Br]₂–ZnBr₄

Molecular ferroelastic materials with high-temperature reversible crystal phase transition behavior are very rare and have currently become one of the hotspots in the field of ferroelastic materials. However, it is still a great challenge to synthesize a high-temperature ferroelastic phase transition material due to the insufficient theoretical knowledge about the structure transition. Here, we try to combine molecular design and crystal engineering to design molecular ferroelastic crystals with high phase transition temperatures. As expected, a new organic–inorganic hybrid, [(CH3)3NCH2Br]2–ZnBr4 (1), is synthesized by molecular modifications, in which the directionality of the halogen···halogen interactions seems to play a crucial role in achieving a much higher temperature phase transition behavior. Intriguingly, the strip-type ferroelastic domains of 1 were observed at room temperature.