A multifunctional molecular ferroelectric with chiral features, a high Curie temperature, large spontaneous polarization and photoluminescence: (C 9 H 14 N) 2 CdBr 4

• Published in: Chemical science (Cambridge) 2021-10, Vol.12 (39), p.13061-13067
• Main Authors: Li, Yu-Kong, Lai, Yuan-Yuan, Ying, Ting-Ting, Han, Ding-Chong, Tan, Yu-Hui, Tang, Yun-Zhi, Du, Peng-kang, Zhang, Hao
• Format: Article
• Language: English
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/D1SC03964D

Low-dimensional chiral organic–inorganic hybrid metal halides have attracted a lot of attention in recent years due to their unique intrinsic properties, including having potential applications in optoelectronic and spintronic devices. However, low-dimensional chiral molecular ferroelectrics are very rare. In this paper, we report a novel zero-dimensional molecular ferroelectric (C 9 H 14 N) 2 CdBr 4 (C 9 H 14 N + = protonated 3-phenylpropylamine), which has obvious dielectric and thermal anomalies and shows a high Curie temperature at 395 K. It crystallizes in the P 2 1 space group at room temperature, showing a strong CD signal, large spontaneous polarization ( P s = 13.5 μC cm −2 ), and a clear ferroelectric domain. In addition, it also exhibits a flexible SHG response. The photoluminescence spectrum shows that 1 has broadband luminescence. At the same time, compound 1 has a wide band gap, which is mainly contributed to by the inorganic CdBr 4 tetrahedron. The high tunability of low-dimensional chiral molecular ferroelectrics also opens up a way to explore multifunctional chiral materials.