CuCl2-H2O体系和FeCl3-H2O体系络合物拉曼光谱研究与溶液拉曼定量分析探索

Raman Spectroscopic Study of the Complex and Quantitative Analysis in the System CuCl_2-H_2O and FeCl_3-H_2O

详细研究了CuCl2-H2O体系和FeCl3-H2O体系络合物拉曼峰。对于CuCl2-H2O体系,认为286cm-1峰可能是[CuCl4]2-和[CuCl6]4-等Cu2+和Cl-形成的各种形式络合物的特征峰叠加的结果,412 cm-1峰可能是以[Cu(H2O)4]2+和[Cu(H2O)6]2+为主的Cu2+的水合物的特征峰叠加在一起形成的;通过对特征峰参数的分析得到了286和412 cm-1特征峰的强度与3 400 cm-1左右水的O—H伸缩振动最强峰强度之比(I1/I3 400和I2/I3 400)以及这两个特征峰的积分面积(A1和A2)和浓度的定量关系曲线,从络合物角度实现了对CuCl2溶液的定量分析。对于FeCl3-H2O体系认为173和331 cm-1两个特征峰可能都是归属于FeCl3在水溶液中最常见的络合形式—[FeCl4]-,173 cm-1峰形很宽可能是由于Fe3+和Cl-形成的其他各种形式络合物,如[FeCl]2+,[FeCl2]+等的特征峰叠加的结果,331 cm-1之后的弱宽峰可能是以[Fe(H2O)4]3+,[Fe(H2O)6]3+为主的Fe3+的水合物的特征峰叠加在一起而形成的;通过对特征峰参数的分析得到了331 cm-1特征峰的积分面积A2以及173和331 cm-1特征峰的积分面积A1和A2之比与浓度的定量关系曲线,从络合物角度实现了对FeCl3溶液的定量分析。

In the present paper, the Raman peaks of complex in the CuCl2-H2O system and FeCl3-H2O system were studied in detail. In the CuCl2-H2O system, the superimposed characteristic peaks of various complex formed by Cu^2＋ and Cl^- （such as [CuCl4 ]^2- and [CuC16]^4-） may be formed the peak of 286 cm^-1, and the superimposed characteristic peaks of various complex formed by Cu^2＋hydrate（[Cu（HzO）4]^2＋ and [Cu（H2O）6]^2＋ based ） may be formed the peak of 412 cm^-1 ; Through the analysis of peak parameters, we has founded two quantitative relationships ： （1） The peak intensity ratio （Ii/I3400 or Iz/I3400 ） of 286 cm1 （or 412 cm^-1 ）and OH stretching Raman spectrum of water （at 3 400 cm^-1 ） and concentration ; （2） The integral area of 286 cm^-1 （or 412 cm^-1 ） and concentration. In the FeCl3-H2O system, 173 and 331 cm ^-1 might be attributed to [-FeCl4]- that is the most common form of FeCl3 complex in aqueous solution. The superimposed characteristic peaks of various complex formed by Fe^3＋ and Cl （such as [-FeCl]^2＋ , [FeCl2]^＋ etc） may be formed the broad peak of 173 cm 1, and the superimposed characteristic peaks of various complex formed by Fe^3＋ hydrate（ [Fe（ H2O） 4 ]^3＋ and [Fe（ Hz O） 6 ]^3＋ based） may be formed the broad weak peak behind of 331 cm^-1. Through the analysis of peak parameters, we has founded two quantitative relationships ： （1）The integral area of 331 cm^-1 （A2） and concentration ; QThe integral area ratio of 173 and 331 cm 1（A1/Az）and concentration.