物理化学学报2012，Vol.28Issue(8)：1823-1829,7.DOI:10.3866/PKU.WHXB201205154
利用超额拉曼光谱研究硝酸镁水溶液中的离子对
Ion Pairs in Aqueous Magnesium Nitrate Solution by Excess Raman Spectroscopy
摘要
Abstract
We study the ion associations in magnesium nitrate solution by Raman spectroscopy. Utilizing the excess spectra and peak decomposition, we analyze the - OH stretching and Nos symmetric stretching regions. Analysis of the - OH stretching region demonstrates that the amount of water molecules in the first hydration shell of the anion follows a linear relationship in the low concentration range (<2.3 mol · kg-1), but deviates from this linear relationship at high concentrations (>2.3 mol · kg-1). The contact ion pairs at high concentration result in the nonlinear variation. In the NO-3 symmetric stretching region, the contact ion pairs and solvent separated ion pairs exist in the Mg(NO3)2 concentration region of 0.23-4.86 mol · kg"'. From a global fitting of the Raman spectra over the whole concentration region, we deduce that the concentration of ion pairs varies. When the Mg(NO,), concentration is below 2.3 mol · kg-1, the relative amounts of all ion pairs increase with the concentration. However, above this concentration, the relative amount of contact ion pairs increases sharply, and solvent separated ion pairs either decrease or increase in their slower rate, until the Mg(Nos): concentration is 3.5 mol ·kg-1, and above this concentration the relative amount of one kind of solvent separated ion pair does not change.关键词
硝酸镁水溶液/直接接触离子对/溶剂分隔离子对/超额拉曼光谱/同时拟合Key words
Aqueous magnesium nitrate solution/ Contact ion pair/ Solvent separated ion pair/ Excess Raman spectrum/ Global fitting分类
化学化工引用本文复制引用
王陈琛,林珂,胡乃银,周晓国,刘世林..利用超额拉曼光谱研究硝酸镁水溶液中的离子对[J].物理化学学报,2012,28(8):1823-1829,7.基金项目
国家自然科学基金(21103158)和高等学校博士学科点专项科研基金(20103402110019)资助项目 （21103158）
