对HA b2+离子的狄基托皮佩拉зин和奥克萨佐隆结构的证据
Brittany R Perkins1, Julia Chamot-Rooke, Sung Hwan Yoon
1Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.
Journal of the American Chemical Society
|November 13, 2009
概括
这项研究揭示,片段分裂产生了二基托皮佩拉зин和氧沙龙结构的混合物,用于b(2)(+) 离子. 这些发现有助于理解的结构和碎片化途径.
科学领域:
- 分析化学 分析化学
- 化学物理 化学物理
- 生物化学 生物化学
背景情况:
- 片段化是质谱学中的一个关键过程.
- 乙二+) 离子可以采用不同的结构异构体,包括oxazolone和diketopiperazine.
- 了解这些结构对于准确的标识和测序至关重要.
研究的目的:
- 为了阐明由质子化HAAAA产生的b(2)(+) 离子的结构性同一性.
- 为了调查oxazolone和diketopiperazine结构在气相中的共存.
- 用计算预测来验证实验发现.
主要方法:
- 红外多光子解离 (IRMPD) 光谱学.红外多光子解离.
- 计算建模 (例如,DFT计算).
- 气相- (H/D) 交换实验. 气相-的交换实验.
主要成果:
- 在IRMPD实验中,b(2)(+) 离子的光谱与deketopiperazine的实验和理论光谱相匹配.
- 在1875厘米的明显的光谱波段 (-1) 表明存在一种oxazolone物种.
- H/D交换证实了两种不同的群体的混合物,与deketopiperazine和oxazolone结构一致.
结论:
- 来自质子化HAAAA的b(2)(+) 离子存在于狄基托皮佩拉和奥克萨龙异构体的混合物中.
- IRMPD光谱和H/D交换是区分这些片段产品的强大工具.
- 这种结构异质性影响了分析和解释.
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