Guo Zheng, Lu Xin
State Key Laboratory of Physical Chemistry of Solid Surface & Center for Theoretical Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
J Phys Chem B. 2006 Jun 1;110(21):10461-6. doi: 10.1021/jp0607972.
We have performed density functional cluster model calculations to explore the mechanism and regioselectivity for the reactions of propylene oxide with X(100)-2x1 surfaces (X = C, Si, and Ge). The computations reveal the following: (i) the reactions on Si(100) and Ge(100) are barrierless and highly exothermic; (ii) the reactions on X(100) (X = Si and Ge) are initiated by the formation of a dative-bonded precursor state followed by regioselective cleavage of the C2-O bond (C2 directly connected to the methyl-substituent) in propylene oxide, giving rise to a five-membered ring surface species; and (iii) the reaction on C(100), although highly exothermic, requires a large activation energy and would be kinetically forbidden at room temperature.
我们进行了密度泛函簇模型计算，以探究环氧丙烷与X(100)-2x1表面（X = C、Si和Ge）反应的机理和区域选择性。计算结果表明：(i) 在Si(100)和Ge(100)上的反应无势垒且高度放热；(ii) 在X(100)（X = Si和Ge）上的反应通过形成配位键合的前驱体状态引发，随后环氧丙烷中C2-O键（C2直接连接到甲基取代基）发生区域选择性裂解，生成五元环表面物种；(iii) 在C(100)上的反应虽然高度放热，但需要较大的活化能，在室温下动力学上是禁阻的。
