Two noncentrosymmetric new crystals with high phase transition temperatures: [(parachloroanilinum+)(18-crown-6)][ClO4-](CH3COCH3) and [(parachloroanilinum+)(18-crown-6)][BF4-](CH3COCH3)

Organic-inorganic hybrid new crystals, [(parachloroanilinum⁺)(18-crown-6)][ClO₄^-](CH₃COCH₃) and [(parachloroanilinum⁺)(18-crown-6)][BF₄^-](CH₃COCH₃), with high phase transition temperatures and noncentrosymmetric structures were grown. Their physical properties, including their structures, phase transitions, and dielectric, piezoelectric and photoluminescent properties, were systematically investigated. A phase transition at 71 °C was successively detected and confirmed by DSC and dielectric measurements. Piezoelectric features were clearly verified by piezoresponse force microscopy. Both compounds show strong and wide photoluminescent properties. All the results make the two compounds promising candidates for potential applications in the piezoelectric and optical fields.