Analysis of unstable species using on-line ESI-MS with an electrolysis cell

使用带有电解池的在线 ESI-MS 分析不稳定物质

基本信息

批准号：
11640617
负责人：
ARAKAWA Ryuichi
金额：
$ 1.41万
依托单位：
Kansai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Electrospray ionization mass spectrometry (ESI-MS) has an attractive advantage of soft ionization. The ESI technique results in the transfer of ions initially present in solution into the gas phase. So it provides a quite simple mass pattern and allows us to determine molecular mass accurately with high sensitivity. An on-line electrospray ionization mass-spectrometric analysis for an electrolysis reaction was developed by the installation of a compact, efficient flow-through cell upstream of an electrospraying needle. The electrode was designed to avoid any reduction of the oxidation products formed during electrolysis. The electrolytic oxidation reaction of a Ru and Os metal complex was carried out to examine the performance of the system. From the electrolysis of [M(bpy)3](PF6)2 (where M=Ru and Os, and bpy=2,2'-bipyridine) we detected the one-electron oxidation product, [M(bpy)3]3+. The electrolysis of [Ru(bpy)2(en)](ClO4)2 (en=ethylenediamine) formed two complex products along with the elimination of two and four hydrogen atoms from the en ligand. The structure of the two complex products was determined to be a monoimine and diimine complex, based on an electrolysis experiment using a deuterium-labeled complex, [Ru(bpy)2(ed)](ClO4)2 (ed=ethylene-d4-diamine, H2N-CD2-CD2-NH2). The results indicate that electrochemical oxidation occurs at the ethylenediamine ligand and that the monoimine complex is a reaction intermediate for the formation of a diimine complex. In addition, the photo ligand substitution reaction of the bisphenanthroline (phen) complex in acetonitrile solution was studied using the same on-line system. We detected monodentate complexes with the en ligand as an intermediate. The difference in the photochemical reactivity of the bpy and the phen complex can be explained by the difference in configurational flexibility in the Ru(II) complexes.

电喷雾电离质谱法（ESI-MS）具有软电离的吸引力。 ESI技术导致最初存在于溶液中的离子转移到气相中。因此，它提供了非常简单的质量模式，并使我们能够以高灵敏度准确地确定分子质量。通过在电喷雾针的上游安装紧凑，有效的流通电池，开发了在线电喷雾电离质谱分析，以进行电解反应。该电极的设计旨在避免电解过程中形成的氧化产物的任何降低。进行了RU和OS金属络合物的电解氧化反应，以检查系统的性能。根据[M（BPY）3]的电解（PF6）2（其中M = RU和OS，以及BPY = 2,2'-二吡啶），我们检测到单电子氧化产物，[M（BPY）3] 3 +。 [RU（BPY）2（en）]（ClO4）2（EN =乙二胺）的电解形成了两种复杂产物，并消除了来自EN配体的两个和四个氢原子。基于使用氘标记的复合物[RU（BPY）2（ED）]（ClO4）2（ED =乙烯-D4---乙烯-D4---二胺，H2N-CD2-CD2-NH2）。结果表明，电化学氧化发生在乙二胺配体处，单胺络合物是形成二胺复合物的反应中间体。此外，使用相同的在线系统研究了乙腈溶液中双氨基链氨氨酸（PEN）复合物的光配体取代反应。我们检测到具有en配体的单次元素复合物作为中间体。 BPY和PEN复合物的光化学反应性差异可以通过RU（II）复合物中构型灵活性的差异来解释。