Unusual reversible fast-response dielectric and nonlinear optical switches in homochiral compounds

Abstract

Abstract Two new materials with a fast dielectric response and a quadratic nonlinear optical switching property, (R)- and (S)-3-hydroxypiperidinium perchlorate ((R)- and (S)-3-HP-ClO4), have been synthesized. The homochirality of the cation causes asymmetry breaking, making the compounds crystallize in a chiral space group with special optical properties. By using differential scanning calorimetry (DSC) measurements, (R)- and (S)-3-HP-ClO4 undergo a typical first-order phase transition at 360 and 352 K, respectively. Similarly, the dielectric constants of the two enantiomers exhibit remarkable step-like anomalies around the phase transition temperatures. Moreover, the two enantiomers both show distinct switchable nonlinear optical (NLO) behaviors, which are caused by order-disorder transitions of the (R)- and (S)-3-(hydroxypiperidinium) cations and perchlorate anions. These findings have great potential in next-generation sensors, switches and actuator devices.