A Computational Investigation of the Substituent Effects on Geometric, Electronic, and Optical Properties of Siloles and 1,4-Disilacyclohexa-2,5-dienes.
A Computational Investigation of the Substituent Effects on Geometric, Electronic, and Optical Properties of Siloles and 1,4-Disilacyclohexa-2,5-dienes.
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DOI：
10.3390/molecules22030370
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发表时间：
2017-02-28
期刊：
影响因子：
--
通讯作者：
Ottosson H
中科院分区：
文献类型：
--
作者：
Denisova AV;Tibbelin J;Emanuelsson R;Ottosson H
采用PBE 0杂化密度泛函理论（DFT）方法对32种不同取代的硅杂环戊二烯1a-1 p和1，4-二硅杂环己-2，5-二烯2a-2 p进行了量子化学计算.取代基包括σ-供电子和吸电子基团，以及π-供电子和吸电子基团，并考察了它们在Si原子或C原子上的作用。重点放在几何形状，前线轨道能量和能量的第一个允许的电子激发。我们分析了两个母体物种对应于HOMO和LUMO的轨道之间的能量变化，这里表示为ΔεHL，其动机是第一次允许的跃迁涉及这些轨道之间的激发。尽管噻咯的ΔεHL和激发能低于1，4-二硅杂环己-2，5-二烯，但后者显示出明显更大的取代变化。噻咯的ΔεHL在4.57-5.35 eV（ΔΔεHL = 0.78 eV）范围内变化，而对于1，4-二硅杂环己-2，5-二烯，其范围为5.49-7.15 eV（ΔΔεHL = 1.66 eV）。第一个允许的跃迁的激发能显示出适度的变化（3.60-4.41 eV），而1，4-二硅杂环己-2，5-二烯的变化几乎是两倍（4.69-6.21 eV）。环丁二硅杂环戊烯联合收割机通过具有比硅杂环戊烯甚至更低的激发能而结合了硅杂环戊烯和1，4-二硅杂环己-2，5-二烯的特征，但对于1，4-二硅杂环己-2，5-二烯的取代，激发能也有广泛的变化（3.47-4.77 eV，变化1.30 eV）。
Thirty two differently substituted siloles 1a–1p and 1,4-disilacyclohexa-2,5-dienes 2a–2p were investigated by quantum chemical calculations using the PBE0 hybrid density functional theory (DFT) method. The substituents included σ-electron donating and withdrawing, as well as π-electron donating and withdrawing groups, and their effects when placed at the Si atom(s) or at the C atoms were examined. Focus was placed on geometries, frontier orbital energies and the energies of the first allowed electronic excitations. We analyzed the variation in energies between the orbitals which correspond to HOMO and LUMO for the two parent species, here represented as ΔεHL, motivated by the fact that the first allowed transitions involve excitation between these orbitals. Even though ΔεHL and the excitation energies are lower for siloles than for 1,4-disilacyclohexa-2,5-dienes the latter display significantly larger variations with substitution. The ΔεHL of the siloles vary within 4.57–5.35 eV (ΔΔεHL = 0.78 eV) while for the 1,4-disilacyclohexa-2,5-dienes the range is 5.49–7.15 eV (ΔΔεHL = 1.66 eV). The excitation energy of the first allowed transitions display a moderate variation for siloles (3.60–4.41 eV) whereas the variation for 1,4-disilacyclohexa-2,5-dienes is nearly doubled (4.69–6.21 eV). Cyclobutadisiloles combine the characteristics of siloles and 1,4-disilacyclohexa-2,5-diene by having even lower excitation energies than siloles yet also extensive variation in excitation energies to substitution of 1,4-disilacyclohexa-2,5-dienes (3.47–4.77 eV, variation of 1.30 eV).
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影响因子：
4.3
作者：
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通讯作者：
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影响因子：
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