The UV spectra of four binuclear sulfur-containing iron nitrosyl clusters, namely, cationic Fe2{[S(CH2)2NH3]2(NO)4}SO4·2.5H20 and Fe2[(SC5H11NO2)2(NO)4]SO4·5H2O, anionic Na2[Fe2(S2O3)2(NO)4]·4H2O, and neutral [Fe2(SC5H6)2(NO)4], were modeled using time-dependent density functional theory (TDDFT) and compared with experimental results. It was determined that the strong bands at 310 and 360 nm in the experimental spectra correspond to electronic transitions (Fe—NO) → π*(Fe—NO), but the unshared electron pairs of sulfur atoms also contribute. The presence of an aromatic ring in the sulfur-containing ligand changes the form of the UV spectrum, as was observed in the experiment. Strong characteristic bands are absent from the theoretical spectra of possible products.

中文翻译：

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双核含硫亚硝酰基铁簇及其分解产物的理论紫外光谱的 TDDFT 建模

四种双核含硫亚硝酰基铁簇，即阳离子Fe2{[S(CH2)2NH3]2(NO)4}SO4·2.5H20和Fe2[(SC5H11NO2)2(NO)4]SO4·5H2O的紫外光谱，阴离子 Na2[Fe2(S2O3)2(NO)4]·4H2O 和中性 [Fe2(SC5H6)2(NO)4]，使用瞬态密度泛函理论 (TDDFT) 建模并与实验结果进行比较。确定实验光谱中 310 和 360 nm 的强谱带对应于电子跃迁 (Fe-NO) → π*(Fe-NO)，但硫原子的非共享电子对也有贡献。正如实验中所观察到的，含硫配体中芳环的存在改变了紫外光谱的形式。可能产品的理论光谱中不存在强特征带。