极性分子键角与键偶极矩的关系.pdf

物理化学学报( Wuli Huarue Xuebao)
Jul
Acta Phys.-Chim.Sin.2016,32(7),1639-1648
1639
Article]
doi:10.3866/PKU.WHXB201604062
www.whxb.pku.edu.cn
极性分子键角与键偶极矩的关系
曹静思韦美菊陈飞武
(北京科技大学化学与生物工程学院化学与化学工程系,功能分子与晶态材料科学与应用北京市重点实验室,北京100083)
摘要:研究了基态极性分子的键角和键偶极矩之间的关系。我们采用原子偶极矩校正的 Hirshfeld(ADCH)电
荷来计算键偶极矩,利用电子的局域函数和键临界点处的局域函数值来分析键的电子结构。通过对WA族
(NVA=C,Si,Ge)、MA族(VA=N,P,As)、VA族(MA=O,S,Se)和VIA族(VIA=F,C?,Br)元素形成的系列共
价型基态分子,以及环状基态分子的键角和键偶极矩数据进行分析,发现在键的电子结构类似的情况下,由
于键偶极矩的排斥作用,这些分子的键角随键偶极矩的增加而增大。这一发现有助于加深我们对分子几何结
构的认识
关键词:极性分子;键角;键偶极矩;原子电荷;电子局域函数
中图分类号:O641
Relationship between the Bond Dipole Moment and
Bond Angle of Polar Molecules
CAO Jing-si WEI Mei-ju CHEN Fei-wu
(Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and
Technology Beijing Beijing Key Laboratory for Science and Application of Functional Molecular and
Crystalline Materials, Beijing 100083, P. R. China
Abstract: The relationshi e ween the bond angle and bond dipole moment is investigated. The atomic dipole
moment corrected Hirsheldadch ) charges are used to calculate the bond dipole moment. The electron
calization function and its values at the bond critical points are exploited to analyze the bonds electronic
structures. Through analyzing the data of a series of covalent compounds formed by the IVA(IVA=C, Si, Ge
VA( VA=N, P, As), VIA(VIA =O, S, Se)and VIA( VIA=F, Cl, Br)group elements, it is found that, owing to the
repulsion of bond dipole moments, the bond angles of these molecules become larger as their corresponding
ond dipole moments increase if the bonds'elec ronic structures are similar. This observation is also true for
the ring molecules studied here, although a stress exists within the ring
Key Words: Polar molecule; Bond angle; Bond dipole moment; Atom charge; Electronic local function
要属性之一。偶极矩的大小反映分子极性的大
分子有很多性质,如偶极矩、电离势、电子小,偶极矩大则分子的极性也大,反之亦然。分
亲和势等2。这些性质常常相互联系,其中一些性子偶极矩可以通过实验方法来测量,如溶液法
质,如偶极矩,可用来解释分子间的弱相互.作分子光谱法,也可以通过量子化学方法计算得
用,或说明分子的几何结构。偶极矩是分子的重到。此外利用分子基函数的偶极矩还可计算分子
Received: January I1, 2016: Revised: April 6, 2016: Published on Web: April 6 2016
Corresponding author. Email chenfeiwuqustb. cn; Tel: +86-10-62332689
The project was supported by the National Natural Science Foundation of China(21173020, 21473008)
国家自然科学基金(21173020,21473008)资助项日
O Editorial office of Acta Physico-chimica Sinica