Division of Complex Systems Spectroscopy, Institute of Physics and Applied Computer Science, Faculty of Applied Physics and Mathematics, Gdansk University of Technology, ul. G. Narutowicza 11/12, 80-233 Gdansk, Poland.
Int J Mol Sci. 2021 Dec 24;23(1):205. doi: 10.3390/ijms23010205.
The interactions of ions with molecules and the determination of their dissociation patterns are challenging endeavors of fundamental importance for theoretical and experimental science. In particular, the investigations on bond-breaking and new bond-forming processes triggered by the ionic impact may shed light on the stellar wind interaction with interstellar media, ionic beam irradiations of the living cells, ion-track nanotechnology, radiation hardness analysis of materials, and focused ion beam etching, deposition, and lithography. Due to its vital role in the natural environment, the pyridine molecule has become the subject of both basic and applied research in recent years. Therefore, dissociation of the gas phase pyridine (CHN) into neutral excited atomic and molecular fragments following protons (H) and dihydrogen cations (H) impact has been investigated experimentally in the 5-1000 eV energy range. The collision-induced emission spectroscopy has been exploited to detect luminescence in the wavelength range from 190 to 520 nm at the different kinetic energies of both cations. High-resolution optical fragmentation spectra reveal emission bands due to the CH(AΔ→XΠ; BΣ→XΠ; CΣ→XΠ) and CN(BΣ→XΣ) transitions as well as atomic H and C lines. Their spectral line shapes and qualitative band intensities are examined in detail. The analysis shows that the H irradiation enhances pyridine ring fragmentation and creates various fragments more pronounced than H cations. The plausible collisional processes and fragmentation pathways leading to the identified products are discussed and compared with the latest results obtained in cation-induced fragmentation of pyridine.
离子与分子的相互作用及其离解模式的确定是理论和实验科学中具有重要意义的挑战性工作。特别是，离子碰撞引发的键断裂和新键形成过程的研究可以揭示恒星风与星际介质的相互作用、离子束辐照活细胞、离子束纳米技术、材料的抗辐射能力分析以及聚焦离子束刻蚀、沉积和光刻。由于吡啶分子在自然环境中具有重要作用，近年来已成为基础和应用研究的主题。因此，实验研究了气相吡啶（CHN）在质子（H）和氘阳离子（H）撞击下分解为中性激发原子和分子碎片的过程，研究范围为 5-1000 eV。利用碰撞诱导发射光谱技术在不同阳离子动能下检测波长范围为 190-520nm 的发光。高分辨率光学碎片光谱揭示了 CH(AΔ→XΠ；BΣ→XΠ；CΣ→XΠ)和 CN(BΣ→XΣ)跃迁以及原子 H 和 C 线的发射带。详细检查了它们的光谱线形状和定性带强度。分析表明，H 辐照增强了吡啶环的断裂，并比 H 阳离子更显著地产生了各种碎片。讨论了导致鉴定产物的可能碰撞过程和碎裂途径，并与最近在阳离子诱导的吡啶碎裂中获得的结果进行了比较。
