Institute of Inorganic Chemistry I, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
Chemistry. 2022 Sep 12;28(51):e202200766. doi: 10.1002/chem.202200766. Epub 2022 Jul 26.
The synthesis and detailed characterization of a new Ru polypyridine complex containing a heteroditopic bridging ligand with previously unexplored metal-metal distances is presented. Due to the twisted geometry of the novel ligand, the resultant division of the ligand in two distinct subunits leads to steady state as well as excited state properties of the corresponding mononuclear Ru(II) polypyridine complex resembling those of prototype [Ru(bpy) ] (bpy=2,2'-bipyridine). The localization of the initially optically excited and the nature of the long-lived excited states on the Ru-facing ligand spheres is evaluated by resonance Raman and fs-TA spectroscopy, respectively, and supported by DFT and TDDFT calculations. Coordination of a second metal (Zn or Rh) to the available bis-pyrimidyl-like coordination sphere strongly influences the frontier orbitals, apparent by, for example, luminescence quenching. Thus, the new bridging ligand motif offers electronic properties, which can be adjusted by the nature of the second metal center. Using the heterodinuclear Ru-Rh complex, visible light-driven reduction of NAD to NADH was achieved, highlighting the potential of this system for photocatalytic applications.
本文报道了一种新型 Ru 多吡啶配合物的合成及详细表征，该配合物含有一个以前未探索过的杂双桥联配体。由于新型配体的扭曲几何形状，配体分为两个不同的亚单位，导致相应单核 Ru(II) 多吡啶配合物的稳态和激发态性质类似于原型 [Ru(bpy)]（bpy=2,2'-联吡啶）。通过共振拉曼和 fs-TA 光谱分别评估最初光激发的定位和长寿命激发态在 Ru 面配体球体上的性质，并通过 DFT 和 TDDFT 计算得到支持。第二个金属（Zn 或 Rh）与可用的双嘧啶类似配位球的配位强烈影响前线轨道，例如通过发光猝灭可以明显看出。因此，新的桥联配体基序提供了可以通过第二个金属中心的性质进行调整的电子性质。使用杂双核 Ru-Rh 配合物，实现了可见光驱动的 NAD 向 NADH 的还原，突出了该体系在光催化应用中的潜力。
