氨基取代脂肪族一元酸的电子结构与化学反应性的讨论

引导和构建结构决定性质的教学思想,理解结构与化学反应性能的关系.通过氨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,在α-氨基癸酸中,(1)-αC-C键自由旋转能垒8.425 1kcal/mol,-αC-N键自由旋转能垒14.042 3kcal/mol,高能构象时分子极性较大,为化学反应活性构象;(2)碳原子电荷密度受到氨基的影响,随着氨基取代位置n增加,-αC、-βC、-γC等碳原子负电荷密度减少;(3)氨基酸的体系能E随氨基与羧基有位置n的关系具有E=-594.804-0.005ln(n)(2≤n≤10),给予阐述.

Structure and Reactivity of Aliphatic Saturated Amino Acids

In this paper,the relationship between structure and reactivity of aliphatic amino acids have been discussed via the stereo effect and electronic structure analysis of aliphatic amino acids,respectively.In the α-amino capric acid,(1) a potential energy plot for rotation about the α-C_1—C_2 bond free rotation energy capacity is 8.425 1 kcal/mol,and the α-C—N bond free rotation is 14.042 3kcal/mol.(2) The C-atom charge density is influenced by azyl and azyl replacine position n increasing,α-C、β-C、γ-C C atom charge density weakening.(3) With the relationship between azyl and a chain n of amino acids is linear,the system energy E=-594.804-0.005ln(n)(2≤n≤10).Some results obtained may be useful as references for teaching.