银纳米光催化4-二乙基对巯基苯胺偶联反应机理的研究

Mechanism study on the photo-driven catalytic coupling reaction of 4-diethylaminobenzenethiol on the silver cluster

采用密度泛函理论(DFT)对4-二乙基对巯基苯胺在Ag5簇上的光诱导催化偶联反应机理进行了理论研究.在B3LYP/6-311+G(d,p)基组水平上(Ag采用赝势基组Lan L2DZ)对反应过程中所有的过渡态、中间体的几何构型进行了优化,通过能量和振动频率分析以及内禀反应坐标(IRC)计算证实了过渡态和中间体的合理性.研究发现4-二乙基对巯基苯胺吸附在银簇上发生偶联反应生成偶氮苯的关键在氨基端两个乙基的脱去,反应过程中存在交叉点,通过"系间窜越"行为才能完成催化偶联过程.

The catalytic coupling reaction mechanism for the transformation from 4 - diethylaminobenzenethiol to 4,4＇ -dimercaptoazobenzene on silver cluster was studied by the density functional theory. All of the reactants, intermediates, transition states and products were optimized With B3LYP method at 6 -311 ＋ G （d, p） basis set （Ag using the pseudo potential basis set of LanL2DZ）. Transition states and intermediates have been confirmed by the corresponding vibration analysis and intrinsic reactions coordinate （IRC）. The core of the production of azobenzene via 4 - DEABT absorbed on the surface of Ag5 clusters in the coupled reaction is the elimination of two ethyl. There are cross points in the reaction process. The catalytic coupling process is needed to complete the ＂ intersystem crossing＂ behavior.