化学学报 ›› 2005, Vol. 63 ›› Issue (16): 1531-1535. 上一篇    下一篇

研究简报

L-丝氨酸在丙二醇-水和丁二醇-水混合溶剂中的体积性质

许莉*,王旭,林瑞森   

  1. (浙江大学化学系 杭州 310027)
  • 投稿日期:2004-01-19 修回日期:2005-05-18 发布日期:2010-12-10
  • 通讯作者: 许莉

Volumetric Properties of L-Serine in 1,2-Propanediol-Water and 1,2-Butanediol-Water Mixed Solvents at 298.15 K

XU Li*,WANG Xu,LIN Rui-Sen   

  1. (Department of Chemistry, Zhejiang University, Hangzhou 310027)
  • Received:2004-01-19 Revised:2005-05-18 Published:2010-12-10
  • Contact: XU Li

利用精密数字密度计测定了L-丝氨酸分别在不同组成的1,2-丙二醇-水和1,2-丁二醇-水混合溶剂中的密度, 计算了丝氨酸的表观摩尔体积、极限偏摩尔体积、迁移偏摩尔体积和理论水化数. 根据结构水合作用模型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, 丝氨酸两性离子头基和亲水侧链与醇分子中—OH基团间的相互作用占主导地位, 导致丝氨酸在醇-水混合溶剂中的迁移偏摩尔体积为正值; 此外, 这种亲水相互作用削弱了丝氨酸带电中心对周围水分子的电致收缩效应, 造成了水化数的减小.

关键词: L-丝氨酸, 1,2-丙二醇, 1,2-丁二醇, 极限偏摩尔体积, 结构相互作用

Densities of L-serine in 1,2-propanediol-water and 1,2-butanediol-water mixed solvents have been measured at 298.15 K by an oscillating-tube densimeter. Apparent molar volumes, limiting partial molar volumes, transfer volumes and hydration numbers for L-serine have been calculated. The transfer volumes from water to alcohol-water mixtures and hydration numbers have been discussed in terms of the structural hydration interaction model. The results show that the transfer volumes of serine from water to alcohol-water mixed solvents are positive and the hydration numbers decrease. These may be regarded as a result of a dominant interaction between —OH group of alcohol and ionic group of serine.

Key words: L-serine, 1,2-propanediol, 1,2-butanediol, limiting partial molar volume, structural interaction