关键词: 乙醇-水溶液, 氢键缔合, 乙醇浓度, 氢核磁共振谱

Abstract:

This paper deals with the interaction between hydrogen bond association and ethanol content in ethanol-water solution by means of ¹ NMR.The results show that（1）the weak hydrogen bond CH…O slightly changes with ethanol concentration;（2）CH₂ is easier to form weak hydrogen bond and is more sensitive to ethanol concentration than—CH₃;and（3） as for the strong hydrogen bond OH…O,OH groups in ethanol molecule are more sensitive to the concentration than water,and the strongest hydrogen bond association occurs at a mole fraction of ethanol（x） of 0.550.Furthermore,according to the association strength of hydrogen bond,the ethanol concentration can be approximately divided into three regions,namely,0x0.236,0.236≤x≤0.735 and 0.735x1.000.In the first region,there is a leading association in water molecule,while in the third region,there is a leading association in ethanol molecule,and,in the second region,the strongest and the widest hydrogen bond association net is formed by the interaction of ethanol and water molecules.

Key words: ethanol-water solution, hydrogen bond association, ethanol concentration, ¹ H NMR