Gerlach Marius, Preitschopf Tobias, Karaev Emil, Quitián-Lara Heidy M, Mayer Dennis, Bozek John, Fischer Ingo, Fink Reinhold F
Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany.
Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Straße 24/25, 14476 Potsdam-Golm, Germany.
Phys Chem Chem Phys. 2022 Jun 29;24(25):15217-15229. doi: 10.1039/d2cp02104h.
HCNO is a molecule of considerable astrochemical interest as a precursor to prebiotic molecules. It is synthesized by preparative pyrolysis and is unstable at room temperature. Here, we investigate its spectroscopy in the soft X-ray regime at the C 1s, N 1s and O 1s edges. All 1s ionization energies are reported and X-ray absorption spectra reveal the transitions from the 1s to the π* state. Resonant and normal Auger electron spectra for the decay of the core hole states are recorded in a hemispherical analyzer. An assignment of the experimental spectra is provided with the aid of theoretical counterparts. The latter are using a valence configuration interaction representation of the intermediate and final state energies and wavefunctions, the one-center approximation for transition rates and band shapes according to the moment theory. The computed spectra are in very good agreement with the experimental data and most of the relevant bands are assigned. Additionally, we present a simple approach to estimate relative Auger transition rates on the basis of a minimal basis representation of the molecular orbitals. We demonstrate that this provides a qualitatively good and reliable estimate for several signals in the normal and resonant Auger electron spectra which have significantly different intensities in the decay of the three core holes.
HCNO作为益生元分子的前体，是一种具有重要天体化学意义的分子。它通过制备热解合成，在室温下不稳定。在这里，我们研究了它在软X射线区域C 1s、N 1s和O 1s边缘的光谱。报告了所有1s电离能，X射线吸收光谱揭示了从1s到π*态的跃迁。在半球形分析仪中记录了芯孔态衰变的共振和正常俄歇电子能谱。借助理论对应物对实验光谱进行了归属。后者使用中间态和终态能量及波函数的价组态相互作用表示法，根据矩理论对跃迁速率和能带形状采用单中心近似。计算得到的光谱与实验数据非常吻合，并且大部分相关谱带都得到了归属。此外，我们提出了一种基于分子轨道的最小基表示法来估计相对俄歇跃迁速率的简单方法。我们证明，这为正常和共振俄歇电子能谱中的几个信号提供了定性良好且可靠的估计，这些信号在三个芯孔衰变过程中的强度有显著差异。
