碳材料用碳源化合物热解机理的理论研究  

Theoretical Research of the Pyrolysis Mechanism of the Carbon Matrix Precursor Used for Carbon Material

作　　者：王惠[1] 冉新权[1] 史启桢[1] 文振翼[2] 翟高红[1] 罗瑞盈[3] 杨延清[4] 

机构地区：[1]西北大学化学系,西安710069 [2]西北大学现代物理研究所,西安710069 [3]北京航空航天大学,北京100083 [4]西北工业大学材料科学系,西安710072

出　　处：《无机化学学报》2000年第6期879-887,共9页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金!( No.596820070);陕西省教委专项基金!(No.99JK100)

摘　　要：运用 Gaussian 98程序包中的 AM1方法，对间二甲苯系列化合物的热反应活性及热裂解机理进行了研究。通过不同温度下标准热力学量的计算和自由基间的轨道能级差的量子化学理论计算，结果表明：（ 1）当温度低于 800℃时 ,对各反应物来说热力学支持的主反应路径均是苯环上甲基 C H键首先断裂。当温度达到 800℃时 ,热裂解路径由首先选择 C H键的断裂变成首先选择苯环与甲基间 C C键的断裂。该结论与实验结果一致；（ 2）各反应物之间的热反应活性由大到小的顺序为： 2,4二甲基苯酚 > 2,4二甲基 1巯基苯 >间二甲苯 > 2,4二甲基 1氰基苯。同时亦说明，自由基之间的前线轨道能级差和热力学量的变化等理论参数一样亦可用于判断间二甲苯系列反应物的热解机理和热反应活性。An advanced research about the pyrolysis mechanism of the series of m xylene compounds was carried out by computing internal energy change， standard enthalpy change, free energy change and entropy change at different temperature regimes and the frontier orbital energy for the 8 types of design pyrolysis processes, using the AM1 method in Gaussian 98 program package. The results show that the the pyrolysis process of these compounds firstly starts from the C H bonds of the methyl on the benzene rings when temperature is lower than 800℃ . When the pyrolysis temperature of these compounds is relatively high（ above 800℃）， C C bonds of between the methyl and the benzene ring break first which is supported by thermodynamic calculation result.This conclusion is in accord with the experimental result. The activity sequence of the series of m xylene compounds is: C8H9OH(d1)>C8H9SH(d2)>C8H10(a)>C8H9CN(d3). At the same time, it also proves that the frontier orbital energy difference is the same as the thermodynamics parameters, so they can be used to the studying of the pyrolysis mechanism and thermoreactive activity of this series of xylene compounds.

关 键 词：碳材料 碳源化合物 热裂解机理 AM1法 间二甲苯 

分 类 号：O625.11[理学—有机化学] O641.1[理学—化学]