First principles studies toward the design of silylene superbases: a density functional theory study.
First principles studies toward the design of silylene superbases: a density functional theory study.
复制标题
硅烯超碱设计的第一性原理研究：密度泛函理论研究。
DOI：
--
复制
发表时间：
2013
影响因子：
2.9
通讯作者：
B. Ganguly
中科院分区：
文献类型：
--
作者：
Abul Kalam Biswas;Rabindranath Lo;B. Ganguly
在本文中，我们首次报道了一些设计的硅烯超碱的DFT计算。这些二价Si（II）化合物可以在气相和溶剂相中充当强中性有机超强碱。在B3 LYP/6-311+G**//B3 LYP/6-31+G* 水平上进行的密度泛函理论计算表明，所设计的硅亚烷基衍生物Si（N <$PY 3）2 [Y = -N <$C（NMe 2）2]（8）可以处于超碱范围，其气相质子亲合能为310 kcal/mol.在THF中，发现计算的8的质子亲和力为327.5 kcal/mol。在B3 LYP/6-311+G ~*//B3 LYP/6-31+G ~* 水平上计算了一些简单硅烯的质子亲合能，与实验测量值符合较好.磷腈基团连接到二价硅中心的甲硅烷基的Si中心的碱性显着提高，并进一步作为第二个质子化位点。发现亚甲硅烷基衍生物8在THF中的计算的第二质子亲和力为285.5kcal/mol。我们已经表明，这种硅烯超碱的二聚和环化的可能性较小，单体形式将比其相应的二聚体更稳定。计算的质子亲合能与甲硅烯体系的HOMO-LUMO能隙和单重态与三重态之间的能量差（ΔES-T）具有良好的相关性。采用等键反应，通过计算硅烯稳定化能（SiSE）来考察硅烯分子的稳定性。硅烯分子的反应性已被提出的亲核性，电负性，和硬度等系统。这些硅烯体系的刘易斯基本性质也进行了探讨。
In this paper we have reported for the first time some designed silylene superbases using DFT calculations. These divalent Si(II) compounds can act as powerful neutral organic superbases in the gas phase and in the solvent phase. The DFT calculations performed with the B3LYP/6-311+G**//B3LYP/6-31+G* level of theory showed that one of the designed silylene derivatives :Si(N═PY3)2 [Y = -N═C(NMe2)2] (8) can fall in the range of hyperbase with gas phase proton affinity ∼310 kcal/mol. In THF the calculated proton affinity of 8 was found to be 327.5 kcal/mol. The proton affinities computed at the B3LYP/6-311+G**//B3LYP/6-31+G* level for some simple silylenes have been found to be good agreement with the corresponding experimentally measured values. Phosphazene groups attached to the divalent silicon center of silylenes enhanced the basicity of the Si center significantly and further acted as a second protonation site. The calculated second proton affinity of the silylene derivative, 8 in THF was found to be 285.5 kcal/mol. We have shown that the dimerization and cyclization of such silyene superbases were less likely and the monomeric forms would be more stable than their corresponding dimers. The calculated proton affinities also showed a good correlation with the HOMO-LUMO energy gap and energy difference between the singlet and triplet states (ΔES-T) of the silylene systems. The isodesmic reactions have been employed to examine the stability of the silylene molecules by calculating the silylene stabilization energy (SiSE). The reactivity of silylene molecules has been presented in terms of the nucleophilicity, electronegativity, and hardness of such systems. The Lewis basic properties of these silylene systems have also been explored.
影响因子：
16.6
作者：
Izquierdo, Javier;Hutson, Gerri E.;Cohen, Daniel T.;Scheidt, Karl A.
通讯作者：
Scheidt, Karl A.
影响因子：
15
作者：
Ruth K. Schmidt;Kristine Muether;Christian Mück‐Lichtenfeld;S. Grimme;M. Oestreich
通讯作者：
Ruth K. Schmidt;Kristine Muether;Christian Mück‐Lichtenfeld;S. Grimme;M. Oestreich