Manipulating Selective Metal‐to‐Metal Electron Transfer to Achieve Multi‐Phase Transitions in an Asymmetric [Fe<sub>2</sub>Co]‐Assembled Mixed‐Valence Chain
Nian‐Tao Yao, Liang Zhao, Yi Cheng, Qiang Liu, Yaming Li, Yin‐Shan Meng, Hiroki Oshio, Tao Liu
Abstract
Abstract Manipulation of multi‐functions in molecular materials is promising for future switching and memory devices, although it is currently difficult. Herein, we assembled the asymmetric {Fe 2 Co} unit into a cyanide‐bridged mixed‐valence chain {[(Tp)Fe(CN) 3 ] 2 Co(BIT)} ⋅ 2CH 3 OH ( 1 ) (Tp=hydrotris(pyrazolyl)borate and BIT=3,4‐bis‐(1H‐imidazol‐1‐yl)thiophene), which showed reversible multi‐phase transitions accompanied by photo‐switchable single‐chain magnet properties and a dielectric anomaly. Variable‐temperature X‐ray structural studies revealed thermo‐ and photo‐induced selective electron transfer (ET) between the Co and one of the Fe ions. Alternating‐current magnetic susceptibility studies revealed that 1 displayed on and off single‐chain magnet behavior by alternating 946‐nm and 532‐nm light irradiation. A substantial anomaly in the dielectric constant was discovered during the electron transfer process, which is uncommon in similar ET complexes. These findings illustrate that 1 provided a new platform for multi‐phase transitions and multi‐switches adjusted by selective metal‐to‐metal ET.