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苯酚的酸性比醇强的教学研讨南京大学化学系有机化学教研室编的《有机化学》教材,在讨论酚羟基的酸性时,用了一个具体的醇——环已醇和苯酚作对比,从结构分析,引出含变的差别,绘出环已醇和苯酚离解的能量变化图,联系电离平衡常数来加以说明。我认为这比仅从酚的羟基中氧原子与苯环形成P—兀共轭,降低了氧原子上电子云密度而利于氢原子离解成质子,易形成稳定的苯氧负离子,从而得出苯酚呈酸性或苯酚比醇的酸性强的结论来,较为严密合理。但对于初学有机化学的学生来说,单看课文,后者较易接受,而前者却比较难懂。南大教材的编者对于学生接受的困难是有所估计的,因而在正文之后,另用了一个比喻来说明。我在处理这部分教材时,采用了边作结构分析,边画能量变化图的办法,一步步引导学生最后作出苯酚的酸性比环己醇强的结论,删去比喻,学生还是容易当堂消化这一部分教学内容的。
Phenol acidic than the alcohol teaching discussion Nanjing University Department of Chemistry Department of Organic Chemistry series of “organic chemistry” teaching materials, in discussing the acidity of phenolic hydroxyl, with a specific alcohol - cyclohexanol and phenol for comparison, from the structural analysis , Leads to the difference with change, draw the cyclohexanol and phenol dissociation energy change diagram, in conjunction with the ionization equilibrium constant to illustrate. I think this is more than just the formation of P-conjugation between the oxygen atom and the benzene ring in the hydroxyl group of the phenol, which reduces the electron cloud density on the oxygen atom and facilitates the dissociation of hydrogen atoms into protons, which leads to the formation of stable phenoxyanions, resulting in phenol Acidic or phenol acid than the strong acid conclusion, more rigorous and reasonable. However, for beginner organic chemistry students, it is easier to understand than to read the text. The latter is more acceptable. The compilation of the textbooks of Nanda is an estimation of the difficulties accepted by the students. Therefore, after the text, another metaphor is used to illustrate this. When I dealt with this part of the teaching materials, I used the analysis of the structure of the side as a guide, and at the same time guided the students to finally make the conclusion that the acidity of phenol was stronger than that of cyclohexanol. By deleting the analogy, students could easily digest This part of the teaching content.