Excitation and dissociation of isolated ions derived from polycyclic aromatic hydrocarbons
Excitation and dissociation of isolated ions derived from polycyclic aromatic hydrocarbons
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多环芳烃衍生的孤立离子的激发和解离
DOI：
10.1021/ja00211a001
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发表时间：
1988
影响因子：
15
通讯作者：
R. Cooks
中科院分区：
文献类型：
--
作者：
S. J. Pachuta;H. I. Kenttaemaa;T. Sack;R. Cerny;K. Tomer;M. L. Gross;R. R. Pachuta;R. Cooks
化学，电子，解吸电离和光电离，连同光解离和高，低能量碰撞活化，用于探测多环芳烃的不寻常的质谱行为。片段化的程度甚至解离产物的类型取决于所使用的活化方法。这是合理的能量沉积功能。用于存款能量的方法在某些情况下也可能有影响。双电荷和质子化分子包括在这里所作的比较。此外，具有不同质量和结构的母离子产生共同的低质量碎片离子组。不同母离子光谱的相似性来自于激发后重排的不寻常倾向。广泛的重排是有利的，因为所研究的离子具有高的内部能量容量，如解离所需的异常大的能量所示。因此，不可逆的开环可能发生，然后消除小的中性分子，形成中间离子共同许多PAH分子。这些离子被认为具有无分支累积双键的结构。它们的进一步碎裂产生一组低质量碎片离子，这些离子对于来自不同PAH分子的所有母离子都是常见的。
Chemical, electron, and desorption ionization and photoionization, together with photodissociation and high- and low-energy collisional activation, are used to probe the unusual mass spectrometric behavior of polycyclic aromatic hydrocarbons. The extent of fragmentation and even the types of dissociation products are dependent on the activation method used. This is rationalized in terms of energy deposition functions. The method used to deposit energy may also have effects in some cases. Doubly charged and protonated molecules are included in the comparisons made here. Furthermore, parent ions having different masses and structures produce common sets of low-mass fragment ions. The similarity in the spectra of different parent ions results from an unusual proclivity for rearrangement after excitation. Extensive rearrangement is favored because the ions studied have high internal energy capacity as indicated by the abnormally large energies required for dissociation. Thus, irreversible ring opening may take place, followed by eliminations of small neutral molecules to form intermediate ions common to many PAH molecules. These ions are suggested to have structures with unbranched cumulated double bonds. Their further fragmentation yields sets of low-mass fragment ions which are common for all parent ions derived from different PAH molecules.