Mahmoodi-Darian Masoomeh, Lundberg Linnea, Zöttl Samuel, Scheier Paul, Echt Olof
Department of Physics, Karaj Branch, Islamic Azad University, Karaj, Iran.
Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020, Innsbruck, Austria.
J Am Soc Mass Spectrom. 2019 May;30(5):787-795. doi: 10.1007/s13361-018-02124-z. Epub 2019 Feb 25.
We report the results of an experimental study of electron ionization of large helium nanodroplets doped with formic acid (FA). Several homologous series of cluster anions are observed, including [FA-H], undissociated FA, and these ions complexed with one or more HO. Some major features resemble those observed upon sputtering of frozen FA films but they differ significantly from results obtained by electron attachment to bare FA clusters in the gas phase. The FA and (HO)[FA-H] series show abrupt onsets above n = 2 and 5, respectively. A prominent resonance in the anion yield occurs at 22.5 eV due to the formation of an intermediate He. Also observed are homologous series of [FA-H] or [FA-H] complexed with helium. The cation chemistry is dominated by the production of protonated formic acid clusters, [FAH], but various other homologous cluster ion series are observed as well. Graphical Abstract.
我们报告了对掺杂甲酸（FA）的大型氦纳米液滴进行电子电离的实验研究结果。观察到了几个同系列的簇阴离子，包括[FA-H]、未解离的FA以及这些离子与一个或多个HO络合的产物。一些主要特征类似于在溅射冷冻FA薄膜时观察到的特征，但与通过气相中电子附着到裸FA簇上获得的结果有显著差异。FA系列和(HO)[FA-H]系列分别在n = 2和5以上显示出突然的起始。由于形成了中间的He，在22.5 eV处阴离子产率出现一个显著的共振。还观察到了与氦络合的[FA-H]或[FA-H]的同系列。阳离子化学主要由质子化甲酸簇[FAH]的产生主导，但也观察到了各种其他同系列的簇离子。图形摘要。
