物理化学学报 >> 1998, Vol. 14 >> Issue (01): 63-67.doi: 10.3866/PKU.WHXB19980112

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取代苯酚中共振增强的分子内氢键

张德纯, 张艳秋, 陆澄容   

  1. 苏州大学化学系，苏州 215006
  • 收稿日期:1997-04-28 修回日期:1997-06-25 发布日期:1998-01-15
  • 通讯作者: 张德纯

Resonance-Assisted Intramolecular Hydrogen Bonding in Substituted Phenols

Zhang De-Chun, Zhang Yan-Qiu, Lu Cheng-Rong   

  1. Department of Chemistry,Suzhou University,Suzhou 215006
  • Received:1997-04-28 Revised:1997-06-25 Published:1998-01-15
  • Contact: Zhang De-Chun

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摘要：

根据晶体结构资料，计算了59个邻位取代苯酚中分子内氢键的几何．在STO－3G水平上计算了一些分子中原子部分电荷．结果表明，酚基氧与苯环上碳之间的键长，酚基上氢原子的部分电荷，酚基所在位置处的苯环环内角与取代苯酚的酸常数pKa均有近似线性关系. 当邻位上存在硝基或羰基时，内氢键由于共振而得到显著的增强，据此可说明这一类酚的显著酸性.

关键词: 取代苯酚, 共振增强的氢键, 分子内氢键, 晶体化学

Abstract:

 Based on the crystal structural data, intramolecular hydrogen bonding (intra-HB) geometries and atomic partial charges at STO-3G level in 59 ortho-substituted phenols were calculated. As shown by the results, the bond lengths between the phenolic oxygen and its attached carbon atoms in benzene ring, the atomic partial charges of the phenolic hydrogen atoms and the endocyclic angles at the phenolic groups, all have approximate linear correlation with the acidic constants of the substituted phenols. There is a significant difference between five- and six-membered intra-HB rings. In most of six-membered rings, intra-HB are strengthened by the resonance, by which the characterictics of intra-GB in phenols could well be rationized.

Key words: Phenols, Resonance-assisted hydrogen bonding, Intramolecular hydrogen bonding, Crystal chemistry