[Raman spectroscopic study of the complex and quantitative analysis in the system CuCl2-H2O and FeCl3-H2O].

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 Cu2+ and Cl- (such as [CuCl4]2- and [CuCl6]4-) may be formed the peak of 286 cm(-1), and the superimposed characteristic peaks of various complex formed by Cu2+ hydrate([Cu(H2O)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 (I1 I3I 400 or I2/I3 400) of 286 cm(-1) (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 Fe3+ 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 Fe3+ hydrate([Fe(H2O)4]3+ and [Fe(H2O)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; (2) The integral area ratio of 173 and 331 cm(-1) (A1/A2) and concentration.