Department of Chemistry, Jinan University, 601 Huang-Pu Avenue West, Guangzhou, 510632, China.
Nat Commun. 2021 Jan 19;12(1):456. doi: 10.1038/s41467-020-20557-7.
The semiclassical models of nonadiabatic transition were proposed first by Landau and Zener in 1932, and have been widely used in the study of electron transfer (ET); however, experimental demonstration of the Landau-Zener formula remains challenging to observe. Herein, employing the Hush-Marcus theory, thermal ET in mixed-valence complexes {[Mo]-(ph)-[Mo]} (n = 1-3) has been investigated, spanning the nonadiabatic throughout the adiabatic limit, by analysis of the intervalence transition absorbances. Evidently, the Landau-Zener formula is valid in the adiabatic regime in a broader range of conditions than the theoretical limitation known as the narrow avoided-crossing. The intermediate system is identified with an overall transition probability (κ) of ∼0.5, which is contributed by the single and the first multiple passage. This study shows that in the intermediate regime, the ET kinetic results derived from the adiabatic and nonadiabatic formalisms are nearly identical, in accordance with the Landau-Zener model. The obtained insights help to understand and control the ET processes in biological and chemical systems.
Landau 和 Zener 于 1932 年首次提出了非绝热跃迁的半经典模型，该模型已被广泛应用于电子转移（ET）的研究；然而，实验证明 Landau-Zener 公式仍然具有挑战性。在此，通过分析相间跃迁吸收率，利用 Hush-Marcus 理论研究了混合价配合物 {[Mo]-(ph)-[Mo]}（n=1-3）中的热 ET，涵盖了非绝热直至绝热极限。显然，Landau-Zener 公式在比理论限制（称为窄回避交叉）更宽的条件范围内在绝热体系中是有效的。中间体系的整体跃迁概率（κ）约为 0.5，这是由单通道和首次多通道贡献的。这项研究表明，在中间体系中，由绝热和非绝热公式推导出的 ET 动力学结果几乎是相同的，符合 Landau-Zener 模型。所获得的见解有助于理解和控制生物和化学体系中的 ET 过程。
