物理化学学报 >> 2004, Vol. 20 >> Issue (01): 55-59.doi: 10.3866/PKU.WHXB20040112

研究论文 上一篇    下一篇

氨基酸在氯乙醇水溶液中的体积性质

许莉;金钰;林瑞森;胡新根   

  1. 浙江大学化学系,杭州 310027;温州师范学院化学系,温州 325000
  • 收稿日期:2003-06-30 修回日期:2003-09-15 发布日期:2004-01-15
  • 通讯作者: 许莉 E-mail:xuli2003@263.net

Volumetric Properties of Amino Acids in 2-chloroethanol-Water Mixed Solvents

Xu Li;Jin Yu;Lin Rui-Sen;Hu Xin-Gen   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027; Department of Chemistry, Wenzhou Normal College, Wenzhou 325000
  • Received:2003-06-30 Revised:2003-09-15 Published:2004-01-15
  • Contact: Xu Li E-mail:xuli2003@263.net

摘要: 利用精密数字密度计测定了甘氨酸、L-丙氨酸和L-丝氨酸在不同质量分数的氯乙醇水溶液中的密度,计算了这些氨基酸在氯乙醇水溶液中的表观摩尔体积、极限偏摩尔体积、迁移偏摩尔体积、理论水化数和体积作用系数,讨论了迁移偏摩尔体积和理论水化数的变化规律. 结果表明,三种氨基酸在氯乙醇水溶液中的迁移偏摩尔体积均为正值, 且随氯乙醇浓度的增大而增大. 氨基酸侧链对迁移偏摩尔体积的贡献与侧链性质密切相关. 三种氨基酸在氯乙醇水溶液中的理论水化数均随溶液中氯乙醇浓度的增加而减小. 甘氨酸与氯乙醇分子间的相互作用主要以1 : 1和1 : 2形式为主, L-丙氨酸和L-丝氨酸与氯乙醇分子间的相互作用主要以1 : 1形式为主.

关键词: 甘氨酸, 丙氨酸, 丝氨酸, 氯乙醇, 偏摩尔体积

Abstract: Densities of glycine, L-alanine and L-serine in 2-chloroethanol-water mixed solvents have been measured at 298.15 K by an oscillating-tube densimeter. Apparent molar volumes, limiting partial molar volumes, transfer partial volumes, hydration numbers and volumetric interaction coefficients for these amino acids have been calculated. The results show that all of the transfer partial volumes from water to 2-chloroethanol-water mixed solvents are positive, and increase with increasing 2-chloroethanol concentration; all the hydration numbers decrease with increasing 2-chloroethanol concentration. From the results of the volumetric interaction coefficients, it is concluded that interaction between glycine and 2-chloroethanol is dominated by 1 : 1 and 1 : 2 forms, and interactions between alanine, serine and 2-chloroethanol molecule are dominated by 1 : 1 form.

Key words: Glycine, Alanine, Serine, 2-Chloroethanol, Partial molar volumes