Recently, under the sponsorship of the initiation and cultivation fund of “Top Ten Science and Technology Issues of Southeast University”, Prof. Xiong Ren’gen’s team from the Key Laboratory of “Molecular Ferroelectric Science and Application” of Jiangsu Province, the School of Chemistry and Chemical Engineering, Southeast University successfully realized the targeted design of molecular ferroelectrics. Their related research achievement titled “Towards Targeted Design of Molecular Ferroelectrics: Modifying Molecular Symmetries and Homochirality”, which was completed by Dr. Zhang Hanyue et al. from Southeast University, was published on the Accounts of Chemical research (IF: 20.955). For over a decade, researchers in Professor Xiong Ren’gen's team has actively responded to the school's call to solve centennial problems. Upon thousands of trials and explorations as if finding a needle in a haystack, just like Edison invented the electric light, they finally made a major breakthrough in the field of molecular ferroelectrics.
The molecular ferroelectric refers to a molecular crystal highlighting spontaneous polarization in a certain temperature range and its spontaneous polarization direction can be redirected with changes in the direction of the external electric field. Professor Xiong Ren’gen’s team succeeded in integrating “the principle of Curie symmetry” (that describes the relationship between the sub-groups before and after the phase transition, where the symmetry group of the low-temperature ferroelectric phase should be the maximum sub-group of the symmetrical group of the high-temperature paraelectric phase along the polarization direction) and the “Neumann principle” (the symmetry of the crystal’s any physical property must be higher than all the symmetrical elements of the crystal point groups); meanwhile, in combination with Landau’s phenomenological theory, the team creatively summarized and proposed the phenomenological design strategy of the targeted design of molecular ferroelectric: the “ball-like-aspheric theory” and the “momentum matching theory”, which has transformed the discovery of molecular ferroelectrics from the gold-washing attempts and explorations into rational targeted design and synthesis. (Zhang Hanyue)