Bouwman Jordy, Horst Stefan, Oomens Jos
Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, NL-6525 ED, Nijmegen, the Netherlands.
Present address: Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden, The Netherlands.
Chemphyschem. 2018 Oct 11;19(23):3211-8. doi: 10.1002/cphc.201800846.
A structural characterization of the products formed in the dissociative electron ionization of adamantane (C H ) is presented. Molecular structures of product ions are suggested based on multiple-photon dissociation spectroscopy using the Free Electron Laser for Infrared eXperiments (FELIX) in combination with quantum-chemical calculations. Product ions are individually isolated in an ion trap tandem mass spectrometer and their action IR spectra are recorded. Atomic hydrogen loss from adamantane yields the 1-adamantyl isomer. The IR spectrum of the C H product ion is best reproduced by computed spectra of 2- and 4-protonated meta-xylene and ortho- and para-protonated ethylbenzenes. The spectrum of the product ion at m/z 93 suggests that it is composed of a mixture of ortho-protonated toluene, para-protonated toluene and 1,2-dihydrotropylium, while the spectrum of the m/z 79 ion is consistent with the benzenium ion. This study thus suggests that adamantane is efficiently converted into aromatic species and astrophysical implications for the interstellar medium are highlighted.
本文介绍了金刚烷（C₁₀H₁₆）的离解电子电离过程中形成产物的结构表征。基于使用用于红外实验的自由电子激光（FELIX）的多光子解离光谱结合量子化学计算，推测了产物离子的分子结构。在离子阱串联质谱仪中单独分离产物离子，并记录其作用红外光谱。金刚烷失去原子氢生成1-金刚烷基异构体。C₁₀H₁₅⁺产物离子的红外光谱最好由2-和4-质子化间二甲苯以及邻位和对位质子化乙苯的计算光谱重现。m/z 93处产物离子的光谱表明它由邻位质子化甲苯、对位质子化甲苯和1,2-二氢环庚三烯鎓的混合物组成，而m/z 79离子的光谱与苯鎓离子一致。因此，本研究表明金刚烷能有效地转化为芳香族物质，并突出了其对星际介质的天体物理学意义。
