| 十顶点闭式杂硼烷结构的密度泛函研究 |
| Density Functional Studies on Structures of Close Heteroboranes |
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| 摘要: 运用G96PW91/6-31+G(3d,2p)方法研究十顶点闭式杂硼烷及其位置异构体的稳定性，为实验合成提供理论预测。就原子半径、电负性等对构型稳定性的影响，杂原子占据a和e位形成的位置异构体的稳定性差异等问题，进行稳定化能、几何构型、NBO原子电荷等的比较，得出了有意义的结论。原子半径小的杂原子易占据a位，形成的杂硼烷稳定性高。电负性大的原子有较强的吸引电子能力，与多个原子的结合能力减弱，价电子离域的能力降低，使三维芳香性降低，稳定性降低。杂原子占据的位置不同，形成产物的结构不同，稳定性也不同。1-PB9H10和1-AsB9H10的稳定性分别低于2-PB9H10和2-AsB9H10。相反地，1-SB9H9和1-SeB9H9的稳定性分别高于2-SB9H9和2-SeB9H9。部分杂硼烷的X-H键呈弱酸性，其余氢原子的反应活性也增加，使其容易结合其他基团形成衍生物。 |
| 关键词: 十顶点闭式杂硼烷 构型稳定性 位置异构体 几何构型 |
| 基金项目: |
| Abstract: 10 vertex close heteroboranes show the widely application potency in synthesis chemistry. By using density functional theory G96PW91/6-31+G(3d,2p), the stabilities of series of close heteroboranes and positional isomers have been studied to prognosticate the structures for experiments. The significant conclusions have been deduced through contrastively discussions that small heteroatoms tend to occupy a position to produce the stable heteroboranes. If the heteroatom with high electronegativity enters into e position to combine with more boron atoms, the structure is unfavorable to three dimensions aromaticity and stabilization. When the heteroatoms occupy the different positions, the different structures and stabilities are produced. It has been concluded that the stabilities of 1-PB9H10 and 1-AsB9H10 are lower than those of 2-PB9H10 and 2-AsB9H10, respectively. In contrast, 1-SB9H9 and 1-SeB9H9 have higher stabilities than 2-SB9H9 and 2-SeB9H9, respectively. The weak acidity at X-H bonds makes molecules dehydrogenate easily to interlink with various radicals. |
| Keywords: 10 vertex close heteroboranes stability of configuration positional isomers geometry |
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| 李平.十顶点闭式杂硼烷结构的密度泛函研究[J].无机化学学报,2007,23(2):258-264. |
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