||Sheng-Qun Su, Shu-Qi Wu, Masato Hagihala, Ping Miao, Zhijian Tan, Shuki Torii, Takashi Kamiyama, Tongtong Xiao, Zhenxing Wang, Zhongwen Ouyang, Yuji Miyazaki, Motohiro Nakano, Takumi Nakanishi, Jun-Qiu Li, Shinji Kanegawa, Osamu Sato,, Water-oriented magnetic anisotropy transition, Nat. Commun., https://doi.org/10.1038/s41467-021-23057-4, 2021.05.
||Shu-Qi Wu, Meijiao Liu, Kaige Gao, Shinji Kanegawa, Yusuke Horie, Genki Aoyama, Hajime Okajima, Akira Sakamoto, Michael L. Baker, Myron S. Huzan, Peter Bencok, Tsukasa Abe, Yoshihito Shiota, Kazunari Yoshizawa, Wenhuang Xu, Hui-Zhong Kou, Osamu Sato, Macroscopic Polarization Change via Electron Transfer in a Valence Tautomeric Cobalt Complex, Nature Communications, https://doi.org/10.1038/s41467-020-15988-1, 2020.04, Polarization change induced by directional electron transfer attracts wide attention for its fast switching rate and potential light control. Here, electronic pyroelectricity was investigated in the crystal of a mononuclear complex, [Co(phendiox)(rac-cth)](ClO4)·0.5EtOH (1·0.5EtOH, H2phendiox = 9, 10-dihydroxyphenanthrene, rac-cth = racemic 5, 5, 7, 12, 12, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecane), which undergoes a two-step valence tautomerism (VT). Correspondingly, pyroelectric current exhibited double peaks in the same temperature domain with the polarization change consistent with the change in dipole moments during the VT process. The time-resolved IR spectroscopy showed that the photo-induced metastable state can be generated within 150 ps at 190 K. Such state can be trapped for tens of minutes at 7 K, revealing that photo-induced polarization change could be realized in this system. These results directly demonstrate that the change in the molecular dipole moments induced by intramolecular electron transfer can introduce a macroscopic polarization change in VT compounds..