摘要
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.
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.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2005年第16期1531-1535,共5页
Acta Chimica Sinica
基金
国家自然科学基金(No.20273061)
浙江省教育厅科研项目(No.20030344)资助项目.
