阴离子对水的羟基伸缩振动拉曼光谱的影响

Effects of Anions on OH Stretching Raman Spectra of Water

通过比较纯水、NaX(X=F,Cl,Br,I)、Na2S、NaOH、NaNO3、Na2CO3、Na2SO4溶液的羟基伸缩振动拉曼光谱,发现所研究的阴离子对水的结构都有破坏作用.通过比较阴离子对水的羟基伸缩振动拉曼光谱的影响,可将所研究的阴离子分为两类,一类阴离子有F-、OH-、S2-、CO33-,另一类阴离子有Cl-、Br-、I-、NO3-和SO24-.它们的主要区别在于对羟基伸缩振动拉曼光谱3600cm-1、2900-3100cm-1处影响不同,产生这些区别的原因在于阴离子与水分子之间氢键的强弱.阴离子对水的羟基伸缩振动拉曼光谱的影响因素有离子半径、离子电荷和离子结构,它们的影响程度为离子结构>离子电荷>离子半径.

Raman spectra of solutions of NaX （X=F, Cl, Br, I）, Na2S, NaOH, NaNO3 Na2CO3 Na2SO4 and water were compared. The results showed that all of the studied anions broke the structure of water. The effects of the studied anions on Raman spectrum of water could be summed up into two kinds. F^-, OH^-, S^2-, CO^2- 3 belonged to one kind, and Cl^-, Br^-, I^-, NO^- 3 and SO^2- 4 belonged to the other. The main differences lay on their effects on 3600 cm^-1 and 2900-3100 cm^-1 of OH stretching Raman spectrum of water. And the reason that conduced to these differences was the intensity of hydrogen bond between anion and water molecule. Parameters of the anion influencing OH stretching Raman spectra of water included ion radius, ion charge and ion structure. The order of their effects on water structure was ion structure 〉 ion charge 〉 ion radius