LINEAR SOLVATION ENERGY RELATIONSHIPS .6. ADDITIONS TO AND CORRELATIONS WITH THE PI-STAR SCALE OF SOLVENT POLARITIES
LINEAR SOLVATION ENERGY RELATIONSHIPS .6. ADDITIONS TO AND CORRELATIONS WITH THE PI-STAR SCALE OF SOLVENT POLARITIES
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DOI：
10.1021/jo01329a001
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发表时间：
1979-01-01
影响因子：
3.6
通讯作者：
TAFT, RW
中科院分区：
文献类型：
--
作者：
KAMLET, MJ;HALL, TN;TAFT, RW
采用溶剂变色比较法，用9种溶剂变色指示剂测定了23种其他溶剂的Ir*值。然后使用溶剂极性-极化率的扩展*标度来分析溶剂对Menschutkin反应速率、过氧酯热分解速率以及四烷基卤化铵在溶剂之间的转移自由能的影响。在溶致变色比较方法系列的第6部分中，我们描述了使用该方法来计算溶剂极性-极化率的*标度，因为它源于并且最适合于关联溶剂对未荷电分子的p-*-TT*和TT-‘TT*电子光谱跃迁的影响。7个主要硝基芳香族指示剂的溶致变色位移被用于构建包含28个溶剂*值的初始标尺；然后通过与包含许多发色类型的另外40个指示剂化合物的ymax结果的相关性，该标度被改进并扩展为72*值。在当前LSER系列的第1部分中，4我们将红外光谱伸展带频率的影响与溶剂Ir*值相关联，并且在第2-45“7部分中，我们报告了光谱和反应性数据与溶剂*和a或*和ç值的线性组合的附加多参数最小二乘关联(来自溶剂氢键供体酸度6”8和溶剂氢键接受者碱度5,910)。Wewish Now to
The solvatochromic comparison method is used with nine solvatochromic indicators to determine ir* values for 23 additional solvents. The expanded* scale of solvent polarity-polarizabilities is then used torationalize solvent effects on rates of a Menschutkin reaction, rates of a peroxyester thermal decomposition, and free energies of transfer of a tetraalkylammonium halide between solvents. It is suggested that theexcellent correlations serve as ultimate vindication of the underlying conceptof linear solvation energy relationships, ie, that when polarity, polarizability, and hydrogen bonding effects are correctly unravelled, solvents exert parallel effects on many chemical properties and reactivity parameters.In part 6 of the SolvatochromicComparison Method series, 3 we described the use of that method to formulate a* scale of solvent polarity-polarizabilities, so named because it derived from and was best fitted to correlate solvent effects on p—*-tt* and tt—‘tt* electronic spectral transitions of unchargedmolecules. Solvatochromic shifts for seven mainly nitroaromatic indicators were used toward the construction of an initial scale comprising 28 solvent* values; this was then refined and expanded to 72* values by correlations with ymax results for 40 additional indicator compounds containing many chromophoretypes. In part 1 of the current LSER series, 4 we related effects on infrared spectral stretch band frequencies to solvent ir* values, and in parts 2-45" 7 we reported additional multiple parameter least-squares correlations of spectral and reactivity data with linear combinations of solvent* and a or* and ß values (from an a scale of solvent hydrogen bond donor acidities6" 8 and a ß scale of solvent hydrogen bond acceptor basicities5, 910). Wewish now to