Structural, spectroscopic and electronic properties of a family of face-shared bi-octahedral Ru complexes with a bridging 2,5-di(2-pyridyl)pyrrolide ligand

• Published in: Dalton transactions : an international journal of inorganic chemistry 2020-06, Vol.49 (21), p.753-759
• Main Authors: Kang, Shi-Rui, Zhou, Zi-Qin, Xiong, Chang-Feng, Liu, Bin, McGrady, John E, Obies, Mohammed, Liu, Chao, He, Piao, Yi, Xiao-Yi
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d0dt01325k

A family of Ru 2 dimers, [Ru 2 (μ-κ 2 N,N′:κ 2 N′,N′′-dpp) 2 (μ-X)(X) 2 ] q + (X = Cl, Br, q = 0 and X = I, q = 1) is synthesized from a [Ru 2 (OAc) 4 Cl] paddlewheel starting material. The neutral products are mixed-valence Ru 2 5+ dimers with a Ru-Ru bond order of 0.5, while the cationic iodide is a Ru 2 6+ dimer with formal bond order of 1.0. The Ru-Ru distance is strikingly independent of the identity of the halide and the oxidation state of ruthenium, most likely a consequence of the small bridging nitrogen which constrains the geometry. The spectroscopic properties (EPR, UV/Vis) of the Br complex are consistent with a large σ-σ* splitting in [Ru 2 (μ-κ 2 N,N′:κ 2 N′,N′′-dpp) 2 (μ-Br)(Br) 2 ]. Herein, we found that nitrogen donor dpp − ligand is flexible and provides a platform for aggregation of Ru 2+ and/or Ru 3+ to give a new type of face-sharing bi-octahedra Ru 2 5+ and Ru 2 6+ dimer featuring of distinct metal-metal bond bond between two ruthenium centres.