We herein report the synthesis, characterizations, and synchrotron X-ray charge-density studies of oxo-centered triruthenium(II,III,III) clusters [Ru₃O(CHCl₂COO)₆(py)₃] (1) and [Ru₃O(CHCl₂COO)₆(CO)(py)₂] (2) (py = pyridine). Dichloroacetate was chosen for its large scattering factor of the Cl atom, and its electron-withdrawing nature results in significant stabilization of the targeted lower-valent Ru₃^II,III,III state in the cluster framework. Multipole analysis revealed that the difference in electron populations between two crystallographically independent Ru centers is small for 1 (Δ = 0.30 e) but large for 2 (Δ = 1.46 e). Remarkable differences between 1 and 2 are also found in their static deformation density maps; substantial local charge depletion was found around the central μ₃O atom for 1, which is less pronounced for 2. According to the topological characterization of Ru−μ₃O bonds associated with the bond critical point, bcp, the electron density, ρ_bcp, is in the range of 0.79–0.89 e Å^–3, and the total energy density, H_bcp, is in the range of −0.21 to −0.05 hartree Å^–3. These findings represent the first charge-density distribution analysis of mixed-valence multinuclear Ru complexes including comparison between 3d and 4d transition-metal systems.

中文翻译：

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由吸电子羧酸盐支持的氧中心三钌簇的合成、电化学、DFT 和同步加速器 X 射线电荷密度研究


我们在此报告了氧代中心三钌 （II，III，III） 簇 [Ru₃O（CHCl₂COO）₆（py）₃] （1） 和 [Ru₃O（CHCl₂COO）₆（CO）（py）₂] （2） （py = 吡啶） 的合成、表征和同步加速器 X 射线电荷密度研究。选择二氯乙酸盐是因为其 Cl 原子的散射因子大，其吸电子性质导致目标低价 Ru₃^{II，III，III} 状态在簇框架中的显着稳定。多极子分析表明，两个晶体学上独立的 Ru 中心之间的电子群差异对于 1 （Δ = 0.30 e） 很小，但对于 2 来说很大 （Δ = 1.46 e）。1 和 2 之间的显著差异也体现在它们的静态变形密度图中;在中心 μ₃个 O 原子周围发现大量的局部电荷耗尽，1 为 1，而 2 则不太明显。根据与键临界点 bcp 相关的 Ru-μ₃O 键的拓扑表征，电子密度 ρ_bcp 在 0.79-0.89 e ^Å-3 的范围内，总能量密度 H_bcp 在 -0.21 至 -0.05 hartree ^Å-3 的范围内。这些发现代表了混合价多核 Ru 配合物的首次电荷密度分布分析，包括 3d 和 4d 过渡金属系统之间的比较。