甘氨酸在DMF/水和乙醇/水混合溶剂中的焓对相互作用

Pairwise Interactions of Enthalphy of Glycine in DMF/Water and Ethanol/Water Mixtures at 298.15 K

利用LKB 2277生物活性检测仪对298.15K时甘氨酸在纯水,DMF/水和乙醇/水混合溶剂(DMF或乙醇的质量分数为0.05～0.45,以10%递增)中的稀释焓进行了测定,并利用维里展开式法关联得到焓对相互作用系数值.结果表明,焓对相互作用系数h^2与溶剂的结构性质密切相关.在DMF/水混合溶剂中,h^2随DMF含量的增加而变得更负;而在乙醇/水混合溶剂中,h^2与乙醇含量近似呈抛物线型关系,在乙醇质量分数为0.25时h^2达到一个极小值.

The enthalpies of dilution of glycine in water, DMF/water and ethanol/water mixtures (in 10% increments ranging from 5% to 45% DMF or ethanol by weight) have been measured with LKB 2277 Bio Activity Monitor at 298.15 K. Calculations show that pairwise enthalpic interaction coefficients h2 is closely connected with solvent structure properties. The values of h2 decrease with increasing DMF concentration in mixed solvents. However, they vary parabolically with ethanol concentration and reach a minimum at 25 % ethanol in ethanol/water mixtures.