美国阿贡国家实验室Karen Mulfort团队用原子对分布函数分析观察双金属Cu/Ru/Os配合物溶液相和固态构象的差异。相关研究成果发表在2021年11月17日出版的《德国应用化学》。

高能X射线散射和对分布函数分析（HEXS/PDF）是揭示缺乏长程有序性的材料结构的有效方法，但对于溶液中的分子络合物中尚未得到充分利用。

该文中，研究人员展示了应用分辨率为0.26的HEXS/PDF来揭示五种双金属Os(II)/Ru(II)/Cu(I)配合物的溶液结构。乙腈溶液中每个络合物的HEXS/PDF证实了每个金属中心的局部配位域中的成对相互作用，以及由12个以上间隔的金属-金属相互作用。将溶液中检测到的金属··金属距离与晶体结构和分子模型中检测到的金属··金属距离进行比较，确认了金属桥配体的畸变是固态所特有的。

研究工作提出了第一个通过直接比较溶液相和固态结构观察亚构象差异的例子，并展示了HEXS/PDF在确定单分子溶液结构方面的潜力。

附：英文原文

Title: Bimetallic Cu/Ru/Os Complexes: Observation of Conformational Differences Between the Solution Phase and Solid State by Atomic Pair Distribution Function Analysis

Author: Zhu-Lin Xie, Xiaolin Liu, Andrew J. S. Valentine, Vincent M. Lynch, David M. Tiede, Xiaosong Li, Karen Mulfort

Issue&Volume: 2021-11-17

Abstract: High-energy X-ray scattering and pair distribution function analysis (HEXS/PDF) is a powerful method to reveal the structure of materials lacking long-range order, but is underutilized for molecular complexes in solution. Here we demonstrate the application of HEXS/PDF with 0.26 resolution to uncover the solution structure of five bimetallic Os(II)/Ru(II)/Cu(I) complexes. HEXS/PDF of each complex in acetonitrile solution confirms the pairwise interactions in the local coordination sphere of each metal center as well as the metal···metal interactions separated by over 12 . The metal···metal distance detected in solution is compared with that from the crystal structure and molecular models to confirm that distortions to the metal bridging ligand are unique to the solid state. This work presents the first example of observing sub- conformational difference by direct comparison of solution phase and solid-state structures and shows the potential for HEXS/PDF in the determination of solution structure of single molecules.

DOI: 10.1002/anie.202111764

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202111764