羰基化合物在Si(100)表面[2+2]环加成和α-H裂解反应的选择性(英文)  

Selectivity of [2+2] C=O Cycloaddition and α-H Cleavage of Carbonyl Compounds on Si(100) Surface

作　　者：张继超[1] 程学礼[2] 程玉桥[1] 孟祥华[2] 刘永军[2] 刘成卜[2] 

机构地区：[1]中国石化胜利油田分公司地质科学研究院,山东东营257015 [2]山东大学化学与化工学院,济南250100

出　　处：《物理化学学报》2012年第8期1849-1853,共5页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China (21173129)~~

摘　　要：最近研究表明:丙酮能与半导体Si(100)表面发生[2+2]环加成和α-H裂解反应形成相应的Si―C键或Si―O键,在半导体材料的合成方面具有重要意义.为进一步弄清不同羰基化合物在Si(100)表面的反应机理,本文应用密度泛函理论方法在B3LYP/6-311++G(d,p)//6-31G(d)水平上较为系统地研究了一系列羰基化合物CH3COR(R=CH3,H,C2H5,C6H5)与Si(100)表面的反应.研究结果表明:不论是[2+2]环加成反应还是α-H裂解反应都对应较低的反应势垒(小于25kJ·mol-1);环加成反应的势垒比α-H裂解反应的势垒略高;羰基上的取代基对反应势垒的影响较少;α-H裂解反应产物为动力学和热力学控制产物;对丁酮来说,1-位和3-位H原子的裂解反应都比较容易,势垒相差很小.这些结果表明羰基化合物与Si(100)表面的反应将得到多种产物.Recent studies have demonstrated that a simple ketone [acetone, （CH3）2C=O）] reacts with the Si（100） surface in a [2＋2] C=O cycloaddition or by α-H cleavage to form Si―C and/or Si―O σ-bonds. To understand the reactivity of carbonyl compounds bearing different substitutes, the [2 ＋ 2] C=O cycloaddition and α-H cleavage of carbonyl compounds CH3COR （R=CH3, H, C2H5, C6H5） on Si（100） surface have been investigated using density functional theory at the B3LYP/6-311 ＋＋ G（d,p）//6-31G（d） level. Our calculation results reveal that： （1） both cycloaddition and α-H cleavage corresponds to very low energy barriers （lower than 25 kJ·mol-1）, and the energy barrier for cycloaddition is slightly higher than α-H cleavage; （2） the substituents on the carbonyl compound [CH3COR] has only a minor influence on the energy barrier; （3） the α-H cleavage reactions are thermodynamically and kinetically more favorable than cycloadditions; （4） for the α-H cleavage of butanone, reactions at C1 and C3 positions are competitive. These findings suggest that the reactions of ketone derivatives with Si（100） surface will generate multiple products.

关 键 词：密度泛函理论:环加成反应:α-H裂解反应:羰基化合物 

分 类 号：O621.25[理学—有机化学]