拉曼光谱研究CaCl_2和MgCl_2对水结构的影响  

Raman Spectroscopic Study of Effect of CaCl_2 and MgCl_2 on Structure of Water

作　　者：李睿华[1] 蒋展鹏[1] 师绍琪[1] 杨宏伟[1] 

机构地区：[1]清华大学环境科学与工程系,北京100084

出　　处：《物理化学学报》2003年第2期154-157,共4页Acta Physico-Chimica Sinica

基　　金：清华大学基础研究基金;清华大学分析基金资助项目~

摘　　要：测试了CaCl2、MgCl2溶液(浓度小于1.0mol·L-1)的OH伸缩振动区域的拉曼光谱.对所得到的拉曼光谱进行了计算机去卷积处理,并由此计算了不同溶液中水的四面体结构的百分数.研究表明,CaCl2、MgCl2对水中四面体结构有破坏作用,且CaCl2的破坏作用比MgCl2大.与17O核磁共振结果对比与分析,认为CaCl2、MgCl2虽然破坏水中的四面体结构,但通过促进含氢键数少的水分子形成氢键,故从总体上促进水的缔合结构.Raman spectra of aqueous solutions of CaCl2 and MgCl2 in the OH stretching region (2 500 to 4 000 cm(-1)) with various concentrations below 1.0 mol (.) L-1 were measured. Computer deconvolutions of the Raman spectra allow the percent of tetrahedral hydrogen bonded structure of water to be determined. It is shown that CaCl2 and MgCl2 break tetrahedral hydrogen bonded structure of water and the breaking effect of Ca2+ is stronger than that of Mg2+. By comparision with results of O-17 NMR, it is deduced that CaCl2 and MgCl2 promote structure of water as a whole by forming hydrogen bondings among water molecules with fewer hydrogen bondings even though they break tetrahedral hydrogen bonded structure of water.

关 键 词：水 拉曼光谱 CACL2 MGCL2 氢键 

分 类 号：O657.3[理学—分析化学]