Su Sheng-Qun, Wu Shu-Qi, Baker Michael L, Bencok Peter, Azuma Nobuaki, Miyazaki Yuji, Nakano Motohiro, Kang Soonchul, Shiota Yoshihito, Yoshizawa Kazunari, Kanegawa Shinji, Sato Osamu
Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
The University of Manchester at Harwell, Didcot, OX11 OFA, United Kingdom.
J Am Chem Soc. 2020 Jul 1;142(26):11434-11441. doi: 10.1021/jacs.0c02257. Epub 2020 Jun 22.
Orbital angular momentum plays a vital role in various applications, especially magnetic and spintronic properties. Therefore, controlling orbital angular momentum is of paramount importance to both fundamental science and new technological applications. Many attempts have been made to modulate the ligand-field-induced quenching effects of orbital angular momentum to manipulate magnetic properties. However, to date, reported changes in the magnitude of orbital angular momentum are small in both molecular and solid-state magnetic materials. Moreover, no effective methods currently exist to modulate orbital angular momentum. Here we report a dynamic bond approach to realize a large change in orbital angular momentum. We have developed a Co(II) complex that exhibits coordination number switching between six and seven. This cooperative dynamic bond switching induces considerable modulation of the ligand field, thereby leading to substantial quenching and restoration of the orbital angular momentum. This switching mechanism is entirely different from those of spin-crossover and valence tautomeric compounds, which exhibit switching in spin multiplicity.
轨道角动量在各种应用中起着至关重要的作用，尤其是在磁性和自旋电子学特性方面。因此，控制轨道角动量对于基础科学和新技术应用都至关重要。人们已经进行了许多尝试来调节配体场诱导的轨道角动量猝灭效应以操控磁性。然而，迄今为止，在分子和固态磁性材料中，所报道的轨道角动量大小的变化都很小。此外，目前还不存在有效的方法来调节轨道角动量。在此，我们报道一种动态键合方法来实现轨道角动量的大幅变化。我们开发了一种钴（II）配合物，其配位数在六和七之间切换。这种协同的动态键合切换引起配体场的显著调制，从而导致轨道角动量的大幅猝灭和恢复。这种切换机制与自旋交叉和价互变异构化合物的机制完全不同，后者表现出自旋多重性的切换。
