三乙四胺钴配合物氧合结构和老化机理

以固相法合成的三乙四胺钴配合物为研究体系,采用正离子电喷雾串联质谱、紫外-可见吸收光谱、拉曼共振光谱和红外光谱等表征手段,研究了配合物与氧分子的相互作用过程及配合物在吸氧过程中的结构变化。结果表明,三乙四胺钴配合物的吸氧过程是一个动态的变化过程,氧合产物由双氧双桥联的氧合配合物CoⅢL-(O2)2-CoⅢL形式向双羟基桥联的老化配合物CoⅢL-(OH)2-CoⅢL形式转变;18O2同位素标记实验验证了Co-O-O-Co的存在。酸解实验说明OH桥联配合物的形成是造成可逆性差的根本原因。这些结果为探知多胺钴配合物的氧合结构和老化机理提供了新的研究方法和实验依据。

Oxygenation Reaction and Aging Mechanism of the Triethylenetetramine Cobalt Complex

The triethylenetetramine-cobalt complex (trien-Co) was synthesized by solid state reaction. The oxygenation of trien-Co and the structure evolution of the oxygenated complexes were investigated by electrospray ionization tandem mass spectrometry, the UV-Vis spectrophotometry, Raman spectrum and Infrared spectroscopy. The experimental results indicated that the uptaking of dioxygen is a dynamic process, and the structures of the oxygenated complex were changed from dinuclear diperoxo-dibridged complex to dinuclear hydroxo-hydroxo dibridge complex in the evolution of oxygenation. ¹⁸O₂ isotope labeling experiments proved the existence of Co-O-O-Co. Furthermore, the acid dissociation tests reveal that the development of hydroxo dibridge species was the reason for the poor reversibility of trien-Co complex. These results provide a new method and experimental basis for investigating the oxygenation and auto-oxidation mechanism of polyamine-Co complexes.