The ethylenediamine-cobalt complex,a known model compound of oxygen carriers, was investigated by electrospray ionization tandem mass spectrometry in this paper. The ethylenediamine-cobalt complex was synthesized by solid state reaction. Two sample systems of the complex, separately exposuring dioxygen for 10 minutes and continuously adsorbing oxygen for 6 days, were selected as investigated objects. Under the electrospray positive ion detection mode, the oxygenated ethylenediamine-cobalt complex dissociated readily to various characteristic fragment ions of the oxygenated complexes. One of the fragment ions (m/z 150.86) of the oxygenated complexes were confirmed by its daughter fragmen ion (m/z 118.85) which just lost a neutral fragment of dioxygen (M=32) by further scan fragmentizing. The experimental results indicated that the uptaking of dioxygen is an ageing process, and the structure of the oxygenated complex was changed from dinuclear peroxo-bridged complex to dinuclear peroxo-hydroxo dibridge complex in the evolution of oxygenation. Based on these results, the possible structures, corresponding fragmentation mechanism and the form of dioxygen existed in the oxygenated complex were proposed. ESI-MS method was confirmed to be an effective technique for characterizing oxygenated complexes and researching the oxygenation.%采用电喷雾多级串联质谱技术对氧载体模型化合物乙二胺钴氧合产物的的质谱裂解规律进行了探讨.以固相法合成的乙二胺钴吸氧初和吸氧6d两个阶段为研究体系,在正离子电喷雾质谱条件下能够清楚地观测到乙二胺钴氧合配合物的特征碎片离子.对其中m/z 150.86的碎片峰进行子离子扫描,可得到失去中性氧分子(M=32)的子离子碎片峰(m/z 118.85),从而可进一步确认其为氧合配合物碎片峰.本文采用电喷雾多级串联质谱技术对吸氧初和吸氧饱和后的两个体系进行了合理的初步探讨,根据所得质谱数据对乙二胺钴氧合产物的结构、裂解规律及氧气的存在形态给出初步合理的推论,结果表明,吸氧过程是一个老化的过程,乙二胺钴配合物从吸氧初到吸氧饱和后,其形态经历了从双核过氧桥联配合物到双核过氧羟基双桥联配合物形态的转变.初步确立电喷雾质谱(ESl-MS)可做为研究氧合反应和表征氧合配合物的有效技术手段.
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