Abstract Solvent basicity and polarity/polarizability parameters are analysed using molecular properties of solvents derived from computational chemistry. The results show that Kamlet and Taft’s measure of hydrogen bond basicity, β, is essentially identical to Gutmann’s donor number, a measure of Lewis basicity, both being determined by the charge on the most negative atom of the solvent molecule and the energy of the electron donor orbital. It is also found that, for both parameters, the calculated values for alcohols and N–H containing bases deviate systematically from those for aprotic solvents. This mirrors Kamlet and Taft’s earlier observation that different solvatochromic probes yield different β values in amphiprotic solvents. Reichardt’s E T (30) and Kamlet, Abboud and Taft’s π * both show direct dependences on the dipole moments and quadrupolar amplitudes of the solvent molecules and, surprisingly, an inverse dependence on the molecular polarizability. Additionally, E T (30) has a strong dependence on the charge on the most positive hydrogen atom of the solvent molecule, reflecting its sensitivity to hydrogen bonding. Unexpectedly, π * shows a dependence on the energy of the electron donor orbital. Kammet and Taaft’s hydrogen bond acidity parameter, α, is discussed in light of the results for π * and E T (30).

中文翻译：

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使用计算化学探索实验溶剂参数——溶剂碱度、酸度和极性/极化率

摘要 使用源自计算化学的溶剂的分子特性分析溶剂碱度和极性/极化率参数。结果表明，Kamlet 和 Taft 的氢键碱度 β 的量度与 Gutmann 的供体数（路易斯碱度的量度）基本相同，两者均由溶剂分子最负原子上的电荷和电子的能量决定供体轨道。还发现，对于这两个参数，醇和含 N-H 碱的计算值与非质子溶剂的计算值有系统的偏差。这反映了 Kamlet 和 Taft 早期的观察，即不同的溶剂致变色探针在两性溶剂中产生不同的 β 值。Reichardt 的 ET (30) 和 Kamlet，Abboud 和 Taft 的 π * 都显示出与溶剂分子的偶极矩和四极振幅的直接相关性，并且令人惊讶的是，与分子极化率呈负相关。此外，ET (30) 对溶剂分子最正氢原子上的电荷有很强的依赖性，反映了其对氢键的敏感性。出乎意料的是，π * 显示出对电子供体轨道能量的依赖性。Kammet 和 Taaft 的氢键酸度参数 α 根据 π * 和 ET (30) 的结果进行讨论。出乎意料的是，π * 显示出对电子供体轨道能量的依赖性。Kammet 和 Taaft 的氢键酸度参数 α 根据 π * 和 ET (30) 的结果进行讨论。出乎意料的是，π * 显示出对电子供体轨道能量的依赖性。Kammet 和 Taaft 的氢键酸度参数 α 根据 π * 和 ET (30) 的结果进行讨论。