温度对LiCl/(DMSO-H2O)溶液影响的2D-IR研究  

Study of Temperature Effect on LiCl/(DMSO-H2O)Solution by 2D-IR

作　　者：吴晓静 李醒醒 李志 程龙玖[2] WU Xiao-jing;LI Xing-xing;LI Zhi;CHENG Long-jiu(School of Chemistry and Chemical Engineering,Hefei University of Technology,Hefei 230009,China;College of Chemistry&Chemical Engineening,Anhui University,Hefei 230601,China)

机构地区：[1]合肥工业大学化学与化工学院,安徽合肥230009 [2]安徽大学化学化工学院,安徽合肥230601

出　　处：《光谱学与光谱分析》2020年第5期1436-1441,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21873001)资助。

摘　　要：对溶液的研究,尤其是金属离子在双溶剂溶液中的研究是化学化工和环境科学等领域的重要环节。传统的溶液分析方法主要是利用一维红外光谱或拉曼光谱等进行分析,但其分辨率低,误差较大,谱峰重叠严重,难以对复杂的体系进行研究。采用二维红外光谱和密度泛函理论相结合的方法,以实现对溶液内团簇的准确分析。利用傅里叶变换红外光谱仪,温度为外扰条件,在4000~400 cm^-1范围内分别对双溶剂DMSO-H2O和Li^+/(DMSO-H2O)溶液体系进行红外光谱实验。对所得数据进行归一化等处理,获得SO双键的一维红外光谱图,发现水的加入使DMSO的SO红外光谱发生了红移,且随着温度的升高SO红外振动强度逐渐增加,Li^+加入使得SO双键强度整体下降,其谱峰重叠严重,难以分析。利用二维红外光谱对溶液中团簇内分子SO双键的类型、动态变化、变化顺序以及锂离子对其的影响进行分析,获得其变化规律,解决了一维红外光谱存在的问题。结合密度泛函理论计算对团簇结构进行优化和分析,证明二维红外光谱分析结果的正确性和可行性,实现理论计算与实验的相互印证,拓宽二维红外光谱与密度泛函理论的研究领域。实验以温度为扰动,针对DMSO-H2O和Li^+/(DMSO-H2O)溶液中团簇内分子SO双键的变化,运用二维红外光谱探讨溶液中微团簇变化规律。研究发现,温度扰动时,溶液的二维同步红外光谱中,在1010,1045,990和1020 cm^-1附近有四个自动峰,说明溶液中团簇内存在甲基的振动,DMSO·H2O、单体以及二聚体DMSO分子团簇的振动;二维异步红外光谱中,发现1010 cm^-1的DMSO·H2O较先变化,说明该团簇对温度扰动更加敏锐。结果表明,结合密度泛函理论计算和二维红外光谱分析能较好地了解溶液中团簇的存在形式及温度扰动对它们的影响与变化规律,实现了一维光谱中由于峰的重叠或变化不明显等对化学信号�The study of the solution,especially metal ions in binary solutions,is an important part in the fields of chemical engineering and environment.The traditional analysis would mainly be the use of one-dimensional Infrared spectroscopy or Raman spectroscopy.However,the resolution ratio of the methods is low,and spectral peaks overlap is serious usually,which will lead to the errors.Two-dimensional infrared spectroscopy(2 D-IR)has its advantage,in this article 2 D-IR and density functional theory have been combined to analysis of the cluster in solution,and the result could satisfactorily be obtained.Firstly using Fourier transform infrared spectroscopy(FTIR)for DMSO-H2O and Li^+/(DMSO-H2O)have been measured in the range of 4000~400 cm^-1 with temperature as external disturbance.One-dimensional infrared spectra of SO double bond could be obtained by normalization of the data.It could be found that the SO of DMSO shifted to red when water was added,and their intensity of SO infrared vibration would increase with the raise of temperature.The intensity of SO double bond would decrease with the addition of Li^+,moreover the overlap of peaks was serious,which would influence to distinguish.2 D-IR would be used to analyze,include its type,dynamic change,change order of molecule in SO double bond and the effect of lithium ion on the solution.And the changing rule could be obtained.The cluster structures have been optimized and analyzed by using density functional theory calculation,and the results could prove that it is useful and feasible.Moreover,both the theoretical calculation and experimental have been used in the verification of the clusters in the solution,and these would expand the researchregion.Therefore,when discussed forDMSO-H2O and LiCl/(DMSO-H2O)by using 2 D-IR with the temperature change.The results of synchronous 2 D-IR have shown that there are four automatic peaks near 1010,1045,990 and 1020 cm^-1 when temperature is perturbed,which indicates that in SO bond exists methyl vibration,DMSO·H2O,monomer and di

关 键 词：二维红外光谱 双溶剂 密度泛函理论 溶剂化作用 

分 类 号：O645[理学—物理化学]