Mijovilovich A, Pettersson L G M, Mangold S, Janousch M, Susini J, Salome M, de Groot F M F, Weckhuysen B M
Inorganic Chemistry and Catalysis group, Debye Institute for Nanomaterials Research, Department of Chemistry, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands.
J Phys Chem A. 2009 Mar 26;113(12):2750-6. doi: 10.1021/jp806823c.
Sulfur K-edge XANES has been measured for three sulfur model compounds, dibenzothiophene, dibenzothiophene sulfone, and aliphatic sulfur (DL-methionine). The spectra have been simulated with Density Functional Theory (DFT) by using a number of methods, including the half-core-hole approximation. Dipole transition elements were calculated and the transitions were convoluted with linearly increasing Gaussian functions in the first 20 eV of the near-edge region. In the case of dibenzothiophene, relaxation of the first excited states in the presence of the core-hole gave a further improvement. The theoretical results reproduce well the features of the spectra and give insight in the relation between geometric structure and molecular orbitals. Though DL-methionine and dibenzothiophene show a similar sharp rise of the white line, their molecular levels are quite different, pointing out the difficulties in finding useful "fingerprints" in the spectra for specific compounds.
已对三种硫模型化合物——二苯并噻吩、二苯并噻吩砜和脂肪族硫（DL-蛋氨酸）进行了硫K边X射线吸收近边结构（XANES）测量。利用密度泛函理论（DFT）通过多种方法对光谱进行了模拟，包括半芯孔近似法。计算了偶极跃迁元素，并在近边区域的前20电子伏特范围内用线性增加的高斯函数对跃迁进行了卷积。在二苯并噻吩的情况下，在存在芯孔的情况下对第一激发态的弛豫进一步改善了模拟效果。理论结果很好地再现了光谱特征，并深入揭示了几何结构与分子轨道之间的关系。尽管DL-蛋氨酸和二苯并噻吩的白线都有类似的急剧上升，但它们的分子能级却大不相同，这表明在光谱中为特定化合物找到有用的“指纹”存在困难。
