Abstract The gas-phase basicity strength order of six alkylamines, namely methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, and triethylamine, was compared using computational chemistry methods. The calculated free energy changes indicate that the overall basicity order is triethylamine>diethylamine>trimethylamine>dimethylamine>ethylamine>methylamine. In addition, the hybridization types of orbitals occupied by lone pair electrons of the six bases show that the N atom in methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, and triethylamine exhibits sp4.16, sp5.09, sp6.08, sp4.07, sp4.83 and sp6.53 hybridizations, respectively, suggesting that the basicity orders are trimethylamine>dimethylamine>methylamine; triethylamine>diethylamine>ethylamine. Integrating computational chemistry into the teaching of organic chemistry has not only deepens students’ understanding of the acid-base theories, but also broadens their perspective on hybrid orbital theory, thereby this method is worthy of widespread promotion and application in chemistry teaching.
LV Ren-Qing, WANG Shu-Tao, WANG Fang, SHEN Guo-Ping. Computational Chemistry Application into Organic Chemistry Teaching: Comparison of Gas-Phase Basicity Strength of Some Alkylamines[J]. Chinese Journal of Chemical Education, 2024, 45(24): 104-109.
