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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 shown that acetone can form [2 + 2] cycloadditions and α-H cleavage reactions with Si-C bonds or Si-O bonds on the Si (100) surface and is of great importance in the synthesis of semiconductor materials In order to further understand the reaction mechanism of different carbonyl compounds on the surface of Si (100), the density functional theory (DFT) method was used to study the reaction mechanism of B3LYP / 6-311 ++ G (d, p) The reaction of a series of carbonyl compounds CH3COR (R = CH3, H, C2H5, C6H5) with the Si (100) surface has been studied systematically.The results show that both [2 + 2] cycloaddition and α-H cleavage reactions (Corresponding to a lower reaction barrier (less than 25 kJ · mol -1; the potential of the cycloaddition reaction is slightly higher than that of the α-H cleavage reaction; the substituents on the carbonyl group have less influence on the reaction barrier; For the methyl ethyl ketone, the cleavage reaction of 1-position and 3-position H atoms are relatively easy, and the difference of potential barrier is very small.These results indicate that the carbonyl compounds react with Si ( 100) The reaction on the surface will result in a wide range of products.