Department of Chemistry and Green-Nano Materials Research Center, College of Natural Sciences, Kyungpook National University, Taegu, South Korea.
J Chem Phys. 2011 Dec 28;135(24):244707. doi: 10.1063/1.3671454.
The surface reaction pathways of isoxazole and oxazole on Si(100)-2 × 1 surface were theoretically investigated. They both form a weakly bound Si-N dative bond adduct on Si(100)-2 × 1 surface. In the case of isoxazole, the barrierlessly formed Si-N adduct is the most important surface product, that cannot be easily converted into other species. On the other hand, a facile concerted 4+2 cycloaddition without involving the initial Si-N dative bond adduct was also found in the case of oxazole adsorption. The existence of Diels-Alder reactions is attributed to the particular arrangement of the two heteroatoms of oxazole in such a way that the two Si-C σ-bonds can be formed in a [4+2] fashion. In short, the unique geometric arrangements and electronegativity of these similar heteroatomic molecules yielded distinctively different surface reaction characteristics.
理论研究了异恶唑和恶唑在 Si(100)-2×1 表面上的表面反应途径。它们都在 Si(100)-2×1 表面上形成了弱束缚的 Si-N 配位键加合物。在异恶唑的情况下，无势垒形成的 Si-N 加合物是最重要的表面产物，不容易转化为其他物种。另一方面，在恶唑吸附的情况下，还发现了一种容易的协同4+2环加成，而不涉及初始 Si-N 配位键加合物。Diels-Alder 反应的存在归因于恶唑中两个杂原子的特殊排列方式，使得两个 Si-C σ 键可以以[4+2]的方式形成。简而言之，这些类似杂原子分子的独特几何排列和电负性导致了截然不同的表面反应特征。
