硝基甲烷在石墨烯表面初始反应机理的理论研究  

Reaction Mechanism of Nitromethane on the Graphene Surface:A Theoretical Study

作　　者：刘英哲[1] 康莹[1] 来蔚鹏[1] 尉涛[1] 葛忠学[1] 

机构地区：[1]西安近代化学研究所,陕西西安710065

出　　处：《含能材料》2015年第9期871-876,共6页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(21403162)

摘　　要：为了考察石墨烯对硝基甲烷(NM)反应机理的影响,采用ONIOM(our Own N-layer Integrated molecular Orbital and molecular Mechanics)方法研究了硝基甲烷在石墨烯表面的三种初始反应,包括NM-亚硝酸甲酯(MN)重排反应、氢迁移重排反应及C—N键均裂反应。结果表明,石墨烯表面影响了NM初始反应过渡态、反应产物的结构及能量。与孤立NM相比,NM在石墨烯表面的三种初始反应活化能依次降低了13.4 k J·mol-1、增加了3.8 k J·mol-1和5.4 k J·mol-1,活化能的顺序由C—N键均裂反应<氢迁移重排反应<NM-MN重排反应变为NM-MN重排反应<C—N键均裂反应<氢迁移重排反应。由于石墨烯的平面结构,导致反应过渡态与反应产物的结构倾向于形成平面结构或重叠式构型,从而能够最大程度地与石墨烯相互作用。To explore the effect of graphene on the reaction mechanism of nitromethane （ NM）, three kinds of initial reactions of NM on grapheme surface including the NM-methyl nitrite（MN） rearrangement reaction, the H-migration rearrangement reaction, and the C--N homolytic cleavage reaction were investigated by the ONIOM （our Own N-layer Integrated molecular Orbital and molecular Mechanics） method. Results show that the structures and energies of initial reaction transitions states of NM and reaction products are influenced by the graphene surface. The graphene surface makes the activation energy of three kinds of initial re- actions decrease 1 3.4 kJ · mo1-1 , increase 3.8 kJ · mo1-1 and 5.4 kJ · mol-1 in the order. The orders of activation energies change from the C--N homolytic cleavage〈the H-migration rearrangement〈the NM-MN rearrangement to the NM-MN rearrangement〈the C--N homolytic cleavage〈the H-migration rearrangement. The reaction transition states and reaction products tend to form planar and eclipsed structures, respectively, leading to the maximization of interactions with graphene surface.

关 键 词：势能面 活化能 反应过渡态 ONIOM方法 

分 类 号：O621.25[理学—有机化学]