对弱非结合性Se...F相互作用及其作为轨道相互作用的非凡性质的定量评估
Michio Iwaoka1, Hiroto Komatsu, Takayuki Katsuda
1Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Journal of the American Chemical Society
|February 28, 2002
概括
研究有机化合物中的-相互作用表明,较低的温度会加强这些键. 量子化学计算证实了轨道相互作用驱动这种现象.
科学领域:
- 有机化学 有机化学
- 物理化学 物理化学
- 计算化学的计算化学
背景情况:
- 此前在o-selenobenzyl化物衍生物中发现了弱分子内非结合性Se...F相互作用.
- 了解这些相互作用的性质和强度对于预测分子行为至关重要.
研究的目的:
- 为了评估核自旋合 (J(Se...F)) 在二-甲基 (甲基) 烯基酸盐 (1a) 和二-甲基 (甲基) 烯基) 脱化物 (1e) 中的温度依赖.
- 为了确定具有和没有Se...F相互作用的适配体的能量稳定性.
- 为了阐明控制Se...F相互作用的电子因素.
主要方法:
- 取决于温度的核磁共振 (NMR) 光谱测量J(Se...F) 合.
- 快速平衡模型分析以评估构造稳定性.
- 量子化学 (QC) 计算和自然键轨道 (NBO) 分析.
主要成果:
- 对于1a和1e,随着温度的下降,J...Se...F显著增加,这表明Se...F相互作用得到加强.
- 结果发现,具有分子内Se...F相互作用的conformer A在度方面比conformer B更稳定.
- 溶剂的影响是最小的,这表明Se...F相互作用的非静电性质,n(F) -->sigma*(Se-X) 轨道重叠是关键因素.
结论:
- 在较低的温度下,内分子Se...F相互作用得到加强.
- 这些相互作用主要是由轨道重叠 (n(F) -->sigma*(Se-X)) 而不是静电力驱动的.
- 这些发现提供了关于有机化合物中非共价键的见解.
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