密度泛函理论及光谱对CuCl_2溶液中微团簇的研究

Study on CuCl_2 in Aqueous Solutions by Density Functional Theory and Raman Spectroscopy

利用密度泛函理论和拉曼光谱对氯化铜溶液第一溶剂化层中的微团簇进行了研究。采用B3LYP方法对溶液中可能存在的团簇构型进行优化,从动力学和热力学方面分析得出溶液中团簇结构信息。理论拉曼光谱在100~500 cm^(-1)主要为Cu—O的伸缩振动峰,3400~4000 cm^(-1)范围内为O—H的对称和不对称伸缩振动。实验光谱在200~340 cm^(-1)出现明显新峰,位于2500~4000 cm-1的O—H伸缩振动峰随着溶液浓度的增加,峰的强度逐渐减小,峰形有明显变化。实验光谱和理论光谱验证和比对,表明溶液的实验光谱中产生的新峰为Cu—O振动,CuCl_2水溶液中产生短程离子相互作用及溶剂化现象,且随着溶液浓度的增加,溶剂化数目减小。

Density functional theory（ DFT） and Raman spectroscopy have been employed in studying on copper chloride solution. The structures have been investigated using B3 LYP,information of the clusters in solution is obtained in the kinetic and thermodynamic analysis. The theoretical Raman spectra in the 100 ～ 500 cm（-1） is mainly Cu—O stretching vibration peak,the symmetric and asymmetric stretching vibration of O—H is located at 3400 ～4000 cm（-1）. Experimental spectra emerge newly peak in the 200 ～ 340 cm（-1）,stretching vibration peak of O—H is located in the 2500 ～ 4000 cm（-1）,with the increase of the solution concentration,stretching vibration peak intensity of O—H decreases gradually and peak shape was changed significantly. A comprehensive conclusion from the theoretical and experimental studies is that the newly peak caused by the vibration of the Cu—O,CuCl_2 present in the aqueous solution can produce the solvation phenomenon,and solvation number decreases with the increase of the solution concentration.