A series of new half-sandwich Ru(II) complex salts of the general formula [(η6-arene)RuX(L)]PF6 (where arene = p-cymene, X = Br and ligand L1 = N-tert-butyl-N-(pyridyl methylene) amine (complex 1), ligand L2 = N-isopropyl-2-pyridine carbaldimine (complex 2), ligand L3 = (2,5-dimethyl-phenyl)-pyridin-2-yl methylene amine (complex 3), ligand L4 = (3,5-dimethyl-phenyl)-pyridin-2-yl methylene (complex 4) and arene = C6H6, X = I, ligand L5 = (4-bromo-phenyl)-pyridin-2-yl methylene (complex 5) have been synthesized by reacting the ruthenium arene precursors [(η6-arene)Ru(μ-X)X]2 with N,N-bidentate ligands in a 1:2 ratio. Full characterization of the complexes was accomplished by physicochemical and spectroscopic methods and X-ray structures of all the complexes 1–5. The crystal structures reveal that the ruthenium centers in 1–5 are coordinated to the N,N-bidentate ligand in a bidentate manner, to the respective halide, and to the arene ring to give a pseudo-tetrahedral geometry around them. The whole arrangement is referred to as the three-legged piano stool, in which the N,N-bidentate ligand and the halide (Br or I) serve as the base occupying three coordination sites, while the arene ring serves as the apex of the stool and occupy the remaining coordination sites.

中文翻译：

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N,N-二齿席夫碱配体的五种芳烃钌(II)配合物与文献中相关配合物的比较结构描述

N-双齿配体以双齿方式连接到相应的卤化物和芳烃环以在它们周围形成假四面体几何形状。整个排列被称为三足钢琴凳，其中N，N-双齿配体和卤化物（Br或I）作为占据三个配位点的碱基，而芳烃环作为其顶点粪便并占据剩余的协调位点。