电喷雾质谱(ESI-MS)是一种软电离质谱技术,已在配合物的结构和机理的研究中显示了重要的作用.本文根据组氨酸钴(CoL2)(L=组氨酸)对分子氧活性很高,极易生成双核氧合配合物(CoL2-O2-CoL2)的特点,采用ESI-MS方法研究了组氨酸钴氧合物(CoL2-O2-CoL2)和组氨酸配合物ML2(M=Cu、Zn).结果发现,质谱图中在相应于双核氧合配合物的高质荷比端(m/z＞ML2),CoL2出现质谱峰,而组氨酸配合物ML2(M=Cu、Zn)在质谱图中高质荷比端没有出现质谱峰,只有配合物ML2的相关峰；这个结果证明了文献报道中的双核氧合配合物(CoL2O2-CoL2)的存在,根据所得质谱结果,初步研究了组氨酸钴双核氧合配合物和ML2配合物的裂解规律.结果表明,可根据质谱数据中有无二聚体形态,做出Co配合物有无吸氧性能的初步判断,因此电喷雾质谱(ESI-MS)可做为研究Co配合物氧合反应和表征Co氧合配合物的有效分析手段.%ESI-MS is a kind of soft ionization mass spectrometric technique; it has proved to be a very important technique in the investigations on structures and mechanisms of complexes. In this paper a comparison study was conducted on the oxygenated cobalt complex of histidine (L) and copper/zinc complex of histidine in oxygen atmosphere since according to literatures among histidine complexes only histidine cobalt complex has a very high affinity to dioxygen and easily form a dinuclear oxygenated complexes (C0L2-O2-C0L2). The ESI-MS results showed that in mass spectrum, the fragment ions corresponding to the dinuclear oxygenated species in higher m/z range (mlz>ML2) were observed for C0L2 while for CuL2 and ZnL2 only fragment ions corresponding to ML2 were observed. Theses results confirmed the dinuclear oxygenated complexes (C0L2-O2-C0L2) existed in the C0L2 complex reported in literature. The possible fragmentation mechanism of CoL2 was proposed. Results from this study proved that ESI-MS could be used as a method to estimate preliminarily if a Co(II) complex have the ability of uptaking dioxygen or not, and it could be used as an effective technique to research the oxygenation and characterize oxygenated Co(Ⅱ) complexes.
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