Unusual high-temperature host–guest inclusion compound-based ferroelectrics with nonlinear optical switching and large spontaneous polarization behaviours

Host–guest inclusion compound-based ferroelectrics [Hcta-(18-crown-6)] + [BF 4 ] − (1) and [Hcta-(18-crown-6)] + [ClO 4 ] − (2) with a high Curie temperature ( T c = 403/394 K) and large spontaneous polarization ( P s = 5.7/4.7 μC cm −2 ) are reported.