The coordination properties of the ditopic oxa-aza macrocycles L1–L3 toward Ni(II) and Co(II) have been investigated by means of potentiometric and UV-vis spectrophotometric measurements. L1–L3 contain two triamine and/or tetraamine chains separated by two dioxa chains and form both mono- and dinuclear complexes in aqueous solution. In the [ML]2+ complexes, the metal ion is coordinated by one of the two polyamine moieties, while the other does not participate in the coordination. In the dinuclear complexes each metal ion is coordinated, almost independently, to a single polyamine moiety. Under aerobic conditions the binuclear Co(II) complexes of the ligands L1–L3 are able to bind molecular oxygen, with a bridging coordination of O2 between the two metals.
通过电位测定法和紫外-可见分光光度法,研究了二位氧杂氮大环 L1-L3 对 Ni(II) 和 Co(II) 的配位特性。L1-L3 包含两条三胺和/或四胺链,由两条二氧杂环链分隔,在
水溶液中形成单核和双核配合物。在 [ML]2+ 复合物中,
金属离子由两个
多胺分子中的一个配位,而另一个不参与配位。在双核配合物中,每个
金属离子几乎独立地与单个
多胺分子配位。在有氧条件下,
配体 L1-L3 的双核 Co(II) 复合物能够与分子氧结合,两种
金属之间有 O2 桥接配位。