A THERMODYNAMIC AND SOLVATOCHROMIC INVESTIGATION OF THE EFFECT OF WATER ON THE PHASE-TRANSFER PROPERTIES OF OCTAN-1-OL
A THERMODYNAMIC AND SOLVATOCHROMIC INVESTIGATION OF THE EFFECT OF WATER ON THE PHASE-TRANSFER PROPERTIES OF OCTAN-1-OL
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DOI：
10.1039/p29920002155
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发表时间：
1992-12-01
期刊：
影响因子：
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通讯作者：
CARR, PW
中科院分区：
文献类型：
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作者：
DALLAS, AJ;CARR, PW
辛烷-1-醇-水分配系数在定量结构-活性关系中发挥了核心作用，并已被应用于药物设计，生物膜模型，以及预测污染物的毒性和运输。水在辛-1-醇中的室温溶解度测定为2.5摩尔dm-3，其相当于摩尔分数0.29。尽管有这种非常高的溶解度，但关于水对辛-1-醇相的化学性质的影响知之甚少。我们已经使用顶空气相色谱法来测量14个化学性质非常不同的溶质，从纯辛-1-醇与水饱和的辛-1-醇的转移自由能。此外，在两个阶段，一系列的11个醇的无限稀释活度系数进行了测量。通常，辛-1-醇中水的存在增加了极性和氢键溶质的浓度，并降低了该相中非极性溶质的浓度。对于所有溶质，水对标准转移自由能变化的影响小于200 cal mol-1。通过研究添加的水对指示剂N，N-二乙基-对硝基苯胺、对硝基苯甲醚、对硝基苯胺、对硝基苯酚、ET-30、双[α-甲基]苯胺、对硝基苯甲醚、对硝基苯胺、对硝基苯酚、ET-30、双[α-甲基]苯胺和对硝基苯甲醚的溶剂化变色性质的影响，验证了这些小的变化。（2-吡啶基）亚苄基-3，4-二甲基苯胺]双（氰基）铁（II）、苯酚蓝和尼罗红的辛-1-醇溶液。无论使用哪种指示剂，添加水对最大吸收波长几乎没有影响。这些结果表明，水几乎完全与辛-1-醇缔合，并且几乎不影响介质的性质。
The octan-1-ol-water partition coefficient has played a central role in quantitative structure-activity relationships and has been applied to drug design, to model biological membranes, and to predict toxicity and transport of pollutants. The room temperature solubility of water in octan-1-ol is determined to be 2.5 mol dm-3, which is equivalent to a mole fraction of 0.29. Despite this very high solubility very little is known about the effect of water on the chemical properties of the octan-1-ol phase. We have used head-space gas chromatography to measure the free energy of transfer of 14 chemically very different solutes, from neat octan-1-ol to octan-1-ol saturated with water. In addition, the infinite dilution activity coefficients of a series of 11 alcohols were measured in both phases. In general, the presence of water in octan-1-ol increases the concentration of polar and hydrogen-bonding solutes and decreases the concentration of non-polar solutes in this phase. For all solutes, the effect of water on the change in the standard free energy of transfer was less than 200 cal mol-1.double dagger These small changes were validated by investigating the effect of added water on the solvatochromic properties of the indicators N,N-diethyl-p-nitroaniline, p-nitroanisole, p-nitroaniline, p-nitrophenol, ET-30, bis[alpha-(2-pyridyl)benzylidene-3,4-dimethylaniline]bis(cyano)iron(II), Phenol Blue, and Nile Red in octan-1-ol. Regardless of the indicator used the addition of water had almost no effect on the wavelength of maximum adsorption. These results show that the water is almost completely associated with octan-1-ol and scarcely effects the properties of the media.