[(Histamine)(18-crown-6) 2 ][BF 4 ] 2 is a high-temperature piezoelectric.

We discovered that [(histamine)(18-crown-6) 2 ][BF 4 ] 2 is a high-temperature host-guest inclusion complex that presents decent piezoelectric properties ( d 33 = 5 pC/N), undergoes a phase transition at 406 K, and also possesses potential ferroelectricity. This work provides a new idea for constructing host-guest inclusion piezoelectrics.