Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore.
J Chem Phys. 2010 Jun 7;132(21):214710. doi: 10.1063/1.3407442.
We previously demonstrated that acetonitrile (N[triple bond]C-CH(3)) binds to the adjacent adatom-rest atom pair of Si(111)-7x7 through a [2+2]-like cycloaddition reaction, forming a (Si)N=C(Si)-CH(3)-like surface species [Tao et al., J. Phys. Chem. B 106, 3890 (2002)]. Current investigation clearly showed that chloroacetonitrile (N[triple bond]C-CH(2)Cl), propargyl chloride (HC[triple bond]C-CH(2)Cl), and 3-chloropropionitrile (N[triple bond]C-CH(2)-CH(2)Cl) react with the surface via enelike reactions, concurrently involving N[triple bond]C/C[triple bond]C as well as the breakage of the C-Cl/C-H bond. Further separation of the unsaturated bond (C[triple bond]C) from the C-Cl bond using CH(2) spacers in 5-chloro-1-pentyne (CH[triple bond]C-CH(2)CH(2)CH(2)Cl) would direct the reaction to a [2+2]-like cycloaddition. These experimental results clearly suggest the possibility of controlling the surface reaction pathways by tuning the organic molecular structures. This strategy can be useful in designing and fabricating functional molecular templates on Si(111)-7x7.
我们之前已经证明，乙腈（N[三重键]C-CH(3)）通过类似于[2+2]的环加成反应与 Si(111)-7x7 的相邻 adatoms-rest 原子对结合，形成一个（Si）N=C(Si)-CH(3)-样的表面物种[ Tao 等人，J. Phys. Chem. B 106, 3890 (2002)]。目前的研究清楚地表明，氯乙腈（N[三重键]C-CH(2)Cl）、丙炔基氯（HC[三重键]C-CH(2)Cl）和 3-氯丙腈（N[三重键]C-CH(2)-CH(2)Cl）与表面通过烯反应，同时涉及 N[三重键]C/C[三重键]C 以及 C-Cl/C-H 键的断裂。在 5-氯-1-戊炔（CH[三重键]C-CH(2)CH(2)CH(2)Cl）中使用 CH(2)间隔物将不饱和键（C[三重键]C）与 C-Cl 键分离，将引导反应向类似于[2+2]的环加成。这些实验结果清楚地表明，通过调整有机分子结构可以控制表面反应途径的可能性。这种策略在设计和制造 Si(111)-7x7 上的功能分子模板时可能非常有用。
