Kamlet-Taft's solvatochromic parameters for nonaqueous binary mixtures between n-hexane and 2-propanol, tetrahydrofurane, and ethyl acetate
Kamlet-Taft's solvatochromic parameters for nonaqueous binary mixtures between n-hexane and 2-propanol, tetrahydrofurane, and ethyl acetate
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DOI：
10.1023/a:1005275432313
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发表时间：
2001-03-01
影响因子：
1.2
通讯作者：
Silber, JJ
中科院分区：
文献类型：
--
作者：
Reta, M;Cattana, R;Silber, JJ
用几种紫外可见吸收探针从光谱数据中测定了正相液相色谱(NPLC)中常用的非水二元混合物，如乙酸乙酯正己烷、四氢呋喃正己烷和异丙醇正己烷的pi*、α和βKamlet-Taft溶剂变色参数。由于在不同的二元混合物中，pI*探针几乎不存在择优溶剂化，因此我们得出的结论是，测量值很好地反映了体溶液的偶极极化率。然而，不同的α和β探针在所研究的所有混合物中的强烈优先溶剂化表明，所获得的溶剂参数更多地反映了溶剂化壳层的性质，而不是主体性质。这一观察结果并不一定意味着获得的阿尔法和贝塔值在多元线性回归(MLR)中没有用处，但应谨慎解释结果，并将视具体情况而定。实际上，只有当研究中的特定溶质优先以类似于阿尔法和贝塔溶剂变色探针的方式溶解时，结果才有意义。
The pi*, alpha, and beta Kamlet-Taft solvatochromic solvent parameters have been determined for nonaqueous binary mixtures commonly used in normal-phase liquid chromatography (NPLC), such as ethyl acetate n-hexane, tetrahydrofurane n-hexane, and 2-propanol n-hexane from spectroscopic data by using several UV-visible absorbing probes. Because preferential solvation is almost nonexistent for the pi* probes in the different binary mixtures, we conclude that the measured values reflect quite well the dipolarity-polarizability of the bulk solution. However, strong preferential solvation for the different alpha and beta probes in all mixtures studied here shows that the solvent parameters obtained reflect the properties of the solvation shell more than the bulk properties. This observation does not necessarily mean that the alpha and beta values obtained will not be useful in multiple linear regressions (MLR), but results should be interpreted with care and will depend on the particular situation. Actually, results will make sense only if the particular solute under study preferentially solvates in a fashion similar to that of the alpha and beta solvatochromic probes.