摘要
采用芘作为荧光探针研究了全组成范围水-甲醇混合溶剂的复合结构.结果表明,芘探针的极性标尺(I1/I3)随体系中甲醇摩尔分数(xm)的增加呈下降趋势,其下降速度对xm变化范围具有明显依赖性,而芘荧光相对量子产率的变化曲线在xm=0.18处呈现出一奇异的极大值.这些结果揭示了在0.18<xm<0.75的很大区间,水(W)与甲醇(M)分子主要形成各种水/醇(W5M1-5)和醇/水(M6W2-4,M8W1-3)复合物,并在xm≈0.50附近发生"水/醇→醇/水"复合结构转变,这一观点为统一目前关于水与甲醇复合结构的两种观点提供了新的依据.
The complex structures in the entire composition range of water-methanol mixture were studied by pyrene fluorescence probe. The results showed that the decrease rate of I1/I3, the pyrene scale for solvent polarity, exhibited clear dependence on the mole fraction （xm） range of methanol in the mixture, while the relative quantum yield of pyrene fluorescence showed a remarkable maximum at xm=0.18. These results revealed that in a wide range of 0.18〈 xm〈0.75, the molecules of water and methanol mainly formed water/methanol （W/M） complexes （W5-M1-5） and methanol/ water （M/W） complexes （M6W2-4, M8W1-3）, and a transition of ＂W/M→M/W＂ complexes would occur at xm ≈ 0.50. This notion provides a conjuncture to reconcile the two existing formulations about water-methanol complexation.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2008年第8期1503-1506,共4页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(20774053,50273014,29928003)
天津市自然科学基金(03380261)资助项目
关键词
水-甲醇
复合结构
芘
荧光探针
氢键
Water-methanol
Complex structure
Pyrene
Fluorescence probe
Hydrogen bond
