A Mixed‐Valence {Fe<sub>13</sub>} Cluster Exhibiting Metal‐to‐Metal Charge‐Transfer‐Switched Spin Crossover
Wen Wen, Yin‐Shan Meng, Cheng‐Qi Jiao, Qiang Liu, Hai‐Lang Zhu, Ya‐Ming Li, Hiroki Oshio, Tao Liu
Abstract
Abstract It is promising and challenging to manipulate the electronic structures and functions of materials utilizing both metal‐to‐metal charge transfer (MMCT) and spin‐crossover (SCO) to tune the valence and spin states of metal ions. Herein, a metallocyanate building block is used to link with a Fe II ‐triazole moiety and generates a mixed‐valence complex {[(Tp 4‐Me )Fe III (CN) 3 ] 9 [Fe II 4 (trz‐ph) 6 ]}⋅[Ph 3 PMe] 2 ⋅[(Tp 4‐Me )Fe III (CN) 3 ] ( 1 ; trz‐ph=4‐phenyl‐4 H ‐1,2,4‐triazole). Moreover, MMCT occurs between Fe III and one of the Fe II sites after heat treatment, resulting in the generation of a new phase, {[(Tp 4‐Me )Fe II (CN) 3 ][(Tp 4‐Me )Fe III (CN) 3 ] 8 [Fe III Fe II 3 (trz‐ph) 6 ]}⋅ [Ph 3 PMe] 2 ⋅[(Tp 4‐Me )Fe III (CN) 3 ] ( 1 a ). Structural and magnetic studies reveal that MMCT can tune the two‐step SCO behavior of 1 into one‐step SCO behavior of 1 a . Our work demonstrates that the integration of MMCT and SCO can provide a new alternative for manipulating functional spin‐transition materials with accessible multi‐electronic states.