An unsymmetrical ligand, 2-(2-pyridinyl)-7-(pyrazol-1-yl)-1,8-naphthyridine (L5) was prepared for the construction of a series of dinuclear complexes. Treatment of L5 with [Ru2(µ-OAc)4Cl] followed by anion metathesis afforded [(L5)(µ-OAc)3Ru2](PF6) (3). Reaction of L5 with 2 equiv. of Ni(OAc)2 provided [Ni4(L5)2(µ-OH)4(CF3COO)2](CF3COO)2 (5). Reaction of [Re2(CO)8(CH3CN)2] with L5 in a refluxing chlorobenzene solution gave a mixture of dirhenium (6) and monorhenium (7) complexes. The monocobalt complex 8 was obtained from complexation of L5 with CoCl2. These new complexes were characterized by elemental analysis and spectroscopic techniques. The structures of complexes 3, 5 and 8 were further confirmed by X-ray crystallography. Nickel complex 5 was evaluated as a catalyst for reduction reactions involving the conversion of ester functionalities into their corresponding alcohols.

中文翻译：

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基于不对称萘啶的四齿配体对各种过渡金属离子的配位化学

不对称配体 2-(2-pyridinyl)-7-(pyrazol-1-yl)-1,8-naphthyridine (L5) 被制备用于构建一系列双核配合物。用 [Ru2(µ-OAc)4Cl] 处理 L5，然后进行阴离子复分解，得到 [(L5)(µ-OAc)3Ru2](PF6) (3)。L5与2当量的反应。Ni(OAc)2 提供 [Ni4(L5)2(μ-OH)4(CF3COO)2](CF3COO)2 (5)。[Re2(CO)8(CH3CN)2]与L5在回流的氯苯溶液中反应得到二铼(6)和一铼(7)配合物的混合物。单钴络合物 8 是由 L5 与 CoCl2 络合得到的。这些新的配合物通过元素分析和光谱技术进行了表征。X射线晶体学进一步证实了配合物3、5和8的结构。