星际介质中的[ SiPAH ]+ π络合物
[SiPAH]+ pi-Complexes in the Interstellar Medium
摘要：
我们调查的存在下，硅原子吸附在星际多环芳烃（PAHs）的表面上形成SiPAH π-复合物。我们使用量子化学计算，以获得中性和阳离子SiPAH复合物的结构，热力学和中红外性能。发现[SiPAH]+复合物的结合能至少为1.5 eV，而其中性对应物的结合能约为0.5 eV。通过对计算的红外光谱进行光谱分析，发现硅与PAH ~+的配位作用对PAH ~+光谱的强度影响不大，但系统地引入了C-C面内和C-H面外谱带的蓝移。[SiPAH]+复合物的热力学数据计算表明，这些物种是稳定的，可以很容易地形成由辐射协会的Si+和PAH物种，已知是丰富的光解区域。它们的中红外指纹显示出由硅的配位引起的特征，这可以解释（i）6.2微米AIB的蓝移位置和（ii）在6.2和11.2微米AIB的蓝色侧上观察到的卫星带的存在。从这样的分配，我们可以推断，通常1%的宇宙硅似乎是连接到多环芳烃。
英文摘要：
We investigate the presence of silicon atoms adsorbed on the surface of interstellar polycyclic aromatic hydrocarbons (PAHs) to form SiPAH pi-complexes. We use quantum chemistry calculations to obtain structural, thermodynamic and mid-IR properties of neutral and cationic SiPAH complexes. The binding energy was found to be at least 1.5 eV for [SiPAH]+ complexes whereas it is roughly 0.5 eV for their neutral counterparts. From the spectral analysis of the calculated IR spectra, we found that the coordination of silicon to PAH+ does not strongly affect the intensities of the PAH+ spectra, but systematically introduces blueshifts of the C-C in-plane and the C-H out-of-plane bands. The thermodynamic data calculated for [SiPAH]+ complexes show that these species are stable and can be easily formed by radiative association of Si+ and PAH species that are known to be abundant in photodissociation regions. Their mid-IR fingerprints show features induced by the coordination of silicon that could account for (i) the blueshifted position of the 6.2 micron AIB and (ii) the presence of satellite bands observed on the blue side of the 6.2 and 11.2 micron AIBs. From such an assignment, we can deduce that typically 1% of the cosmic silicon appears to be attached to PAHs.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
