N_2O分子特殊结构形成机制的定性理论研究  

A qualitative study on the structure formation mechanism of the N_2O molecule

作　　者：廖荣宝[1] 朱云[1] 师瑞娟[1] 管清梅[1] 刘俊龙[1] 

机构地区：[1]阜阳师范学院化学化工学院,安徽阜阳236000

出　　处：《计算机与应用化学》2015年第2期239-242,共4页Computers and Applied Chemistry

基　　金：阜阳师范学院自然科学项目(2013FSKJ05ZD)

摘　　要：直线型N_2O分子的最稳定构象为N-N-O结构,而非N-O-N结构。为了解释N-N-O这一特殊结构的合理性和稳定性,本文利用分子点群的方法,构建了直线型N_2O的σ和π分子轨道:并依据分子轨道的电子划分规则得出直线型N_2O分子中两端位置电子分布多于中间位置。由于O的电负性大于N,所以O原子会优先占据分布较多电子的两端位置,因此,N-N-0结构比N-O-N结构更为合理。The molecule N_2O has two possible geometries, one is N-O-N, the other is N-N-O, and the symmetry of the N-O-N is higher than the N-N-O. However, the more stable conformation of N_2O is N-N-O instead of N-O-N. In order to interpret the stability difference between N-N-O and N-O-N, the molecular orbital method based on point group theory is employed to construct the σ and π orbital of the N_2O. The a orbital is formed by spz hybrid orbital of the three atoms, the π orbital is formed by thepx and py orbitals of the three atoms. There are totally 16 valence electrons in N_2O, according to the molecular orbital method, 4 electrons will populated on the two bonding a orbitals, 4 electrons will populated on the two nonbonding orbitals, 4 electrons will populated on the two bonding n orbitals, and the other 4 electrons will populated on the two nonbonding n orbitals. All the 16 valence electrons are further divided into three parts to allocate to the three atoms according to the coefficient of the atom in the molecular orbital. For both conformations of N-O-N and N-N-O, the middle atom will get 4 electrons. However, the side atom will get 6 electrons. Therefore, considering of the stronger electronegativity of the O than N, the N-N-O geometry is more superior to the N-O-N geometry.

关 键 词：N_2O 分子点群 电荷分布 离域分子轨道 价层轨道 

分 类 号：O641.12[理学—物理化学]