Bistable Multifunctionality and Switchable Strong Ferromagnetic-to-Antiferromagnetic Coupling in a One-Dimensional Rhodium(I)鈥揝emiquinonato Complex

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• 作者：Minoru Mitsumi ; Takashi Nishitani ; Shota Yamasaki ; Nayuta Shimada ; Yuuki Komatsu ; Koshiro Toriumi ; Yasutaka Kitagawa ; Mitsutaka Okumura ; Yuji Miyazaki ; Natalia G贸rska ; Akira Inaba ; Akinori Kanda ; Noriaki Hanasaki
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：May 14, 2014
• 年：2014
• 卷：136
• 期：19
• 页码：7026-7037
• 全文大小：595K
• 年卷期：v.136,no.19(May 14, 2014)
• ISSN：1520-5126

文摘

We present a comprehensive study of the synthesis, heat capacity, crystal structures, UV鈥搗is鈭扤IR and mid-IR spectra, DFT calculations, and magnetic and electrical properties of a one-dimensional (1D) rhodium(I)鈥搒emiquinonato complex, [Rh(3,6-DBSQ-4,5-(MeO)₂)(CO)₂]_{鈭?/sub> (3), where 3,6-DBSQ-4,5-(MeO)2^{鈥⑩€?/sup> represents 3,6-di-tert-butyl-4,5-dimethoxy-1,2-benzosemiquinonato radical anion. The compound 3 comprises neutral 1D chains of complex molecules stacked in a staggered arrangement with short Rh鈥揜h distances of 3.0796(4) and 3.1045(4) 脜 at 226 K and exhibits unprecedented bistable multifunctionality with respect to its magnetic and conductive properties in the temperature range of 228鈥?07 K. The observed bistability results from the thermal hysteresis across a first-order phase transition, and the transition accompanies the exchange of the interchain C鈥揌路路路O hydrogen-bond partners between the semiquinonato ligands. The strong overlaps of the complex molecules lead to unusually strong ferromagnetic interactions in the low-temperature (LT) phase. Furthermore, the magnetic interactions in the 1D chain drastically change from strongly ferromagnetic in the LT phase to antiferromagnetic in the room-temperature (RT) phase with hysteresis. In addition, the compound 3 exhibits long-range antiferromagnetic ordering between the ferromagnetic chains and spontaneous magnetization because of spin canting (canted antiferromagnetism) at a transition temperature TN of 14.2 K. The electrical conductivity of 3 at 300 K is 4.8 脳 10鈥? S cm鈥?, which is relatively high despite Rh not being in a mixed-valence state. The temperature dependence of electrical resistivity also exhibits a clear hysteresis across the first-order phase transition. Furthermore, the ferromagnetic LT phase can be easily stabilized up to RT by the application of a relatively weak applied pressure of 1.4 kbar, which reflects the bistable characteristics and demonstrates the simultaneous control of multifunctionality through external perturbation.}}