苯基取代脂肪族一元酸的电子结构与化学反应性的讨论

Structure and Reactivity of Phenylaliphatic Acids

通过苯基取代直链型脂肪族羧酸化合物的空间构象和电子结构分析,α-苯基癸酸的羧基C—C单键能垒达791.9584kcal/mol,α-C—Ph单键旋转能垒达205.5113kcal/mol,α-苯基癸酸的α-C—C和α-C—Ph单键空间效应较大;苯基对羧酸化合物有吸电子作用;苯基对羧酸的离解能力变化随苯基与羧基的距离增加而减小,这种变化规律的位置在癸酸的奇数位比偶数位使羧基H的电荷密度减少明显,可形成2条趋一点的曲线;α-苯基癸酸的反应性比β-苯基癸酸的反应性好,β-苯基癸酸比γ-苯基癸酸反应性大,苯基癸酸比对应癸酸的化学反应活性大.

In this paper, the relationship between the structure and reactivity of phenylaliphatic acids is discussed via the stereo effect and electronic structure analysis of phenylaliphatic acids, respectively. In the α-phenylcapric acid, a potential energy plot for rotation about the α-C1-C2 bond is 791. 9584 kcal/ tool. the dissociation ability of the carboxylic acid is up to distance of phenyl and carboxyl to increase but reduc. The charge density of H atom weskening with distance down a chain. Some results obtained may be useful as references for teaching.