NO^+和C_6H_6相互作用的理论研究  

A theoretical study on interaction between NO^+ and C_6H_6

作　　者：曾荣英[1] 邝代治[1,2] 冯泳兰[1,2] 唐文清[1,2] 

机构地区：[1]衡阳师范学院化学与材料科学系,湖南衡阳421008 [2]功能金属有机材料湖南省普通高等学校重点实验室,湖南衡阳421008

出　　处：《计算机与应用化学》2011年第10期1330-1334,共5页Computers and Applied Chemistry

基　　金：湖南省教育厅教改课题([2008]263-148);院青年骨干教师经费资助和学院教改课题(jykt200911)

摘　　要：[C_6H_6NO]^+离子,在芳香化合物的亚硝化反应中,可形成两类较为重要的中间体。用密度泛函理论,在B3LYP/6-311++G^(**)基组水平上对NO^+…C_6H_6复合物体系的两类中间体可能构型进行了自由优化,得到了13个能量极小的复合物。结果显示,NO^+和C_6H_6结合方式分三类:(a)～(e)为第Ⅰ类,结构为NO^+中的N或O原子与苯环以π-π堆积作用结合形成的π复合物;(f)～(j)为第Ⅱ类,结构为C2原子上的H转移到苯环的其它C上形成σ复合物;(k)～(m)为第Ⅲ类,结构为C2原子上的H转移到N或O原子上,形成质子转移σ复合物。在考虑零点能(ZEP)和基函数重叠误差(BSSE)校正基础上,得到了各复合物的结合能。通过计算得出,第Ⅰ类复合物的结合能在(153～199)kJ/mol之间,第Ⅱ类复合物的结合能在(83～92)kJ/mol之间,第Ⅲ类复合物的结合能在(189～244)kJ/mol之间,其中复合物的最稳定构型为第Ⅲ类σ复合物中的m结构,即质子H连在N原子上的结构,其结合能为-243.93 kJ/mol。复合物的键长、原子净电荷等都表明,NO^+与C_6H_6结合时电子从苯环向NO^+转移,形成电荷转移复合物。理论振动频率分析与实验IRMPD所得图形相似,且计算得到NO^+与C_6H_6形成复合物后,所有构型的N-O的伸缩振动频率均是降低的,发生红移现象。[C6H6NO]^＋ ions, in two isomeric forms involved as key intermediates in the aromatic nitrosation reaction, have been produced in the gas phase and calculated by density functional theory（DFT）. The calculations about the interaction between nitrogen monoxide cation and benzene have been made and thirteen isomers with minimum energies have been obtained by the B3LYP/6-31 I＋＋G＊＊. Based on the calculated results that NO^＋...C6H6 complexes could be divided into three groups： （a）-（e） for class I, n complexes are formed which both N and O of NO＋ are located above the benzene ring, （f）-（j） for class II, a-complexes which the H proton is covalently bound to one of the ring carbon atoms, （k）-（m） for class III, a-complexes which H proton of C2 was transfered to N or O atom of NO＋. The interaction energies was evaluates with basis set superposition error correction （BSSE） and zero point energy correction（ZPE）, which are in the range of （153-199） kJ/mol for class I, （83-92） kJ/mol for class II, （189-244） kJ/mol for class III. The calculation results show that the most stable geometry of NO^＋^…C6H6 complexes is a-complex （m） with the proton H connected to N atom, which the interacton energy is -243.93 kJ/mol. The bond lengths, total atomic charge of the complexes indicate that electron is transferred from the benzene to the NO^＋, and this gives charge transfer complexes. The IRMPD spectra were compared with the IR absorption spectra calculated for the optimized structures of potential isomers, thus allowing structural information on the absorbing species. Calculated IR spectra for [C6H6NO]＋ isomers displaied a strongly active mode at N-O stretching, and N-O bond stretching mode reported in the （2116.5-2165.6） cm^-1 range for （a）-（e） complexes, （1605.0-1696.1） cm^-1 for （f）-（j）, （1200-1500） cm^-1 for （k）-（m）. Comparing with NO^＋, the frequencies of N-O bond in all complexes is shifted to infrared region.

关 键 词：密度泛函理论 NO^+ C_6H_6 分子间复合物 相互作用 

分 类 号：TQ015.9[化学工程] TP391.9[自动化与计算机技术—计算机应用技术]