Tao Feng, Chen Xian Feng, Wang Zhong Hai, Xu Guo Qin
Department of Chemistry, National University of Singapore, 10 Kent Ridge, Singapore, 119260.
J Am Chem Soc. 2002 Jun 19;124(24):7170-80. doi: 10.1021/ja012563w.
The cumulative double bond (C[double bond]C[double bond]N), an important intermediate in synthetic organic chemistry, was successfully prepared via the selective attachment of acrylonitrile to Si(111)-7 x 7. The covalent binding of acrylonitrile on Si(111)-7 x 7 was studied using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning tunneling microscopy (STM) and DFT calculations. The observation of the characteristic vibrational modes and electronic structures of the C[double bond]C[double bond]N group in the surface species demonstrates the [4 + 2]-like cycloaddition occurring between the terminal C and N atoms of acrylonitrile and the neighboring adatom-rest atom pair, consistent with the prediction of DFT calculations. STM studies further show the preferential binding of acrylonitrile on the center adatom sites of faulted halves of Si(111)-7 x 7 unit cells.
累积双键（C[双键]C[双键]N）是合成有机化学中的一种重要中间体，通过将丙烯腈选择性地附着到Si(111)-7×7上成功制备。使用高分辨率电子能量损失谱（HREELS）、X射线光电子能谱（XPS）、紫外光电子能谱（UPS）、扫描隧道显微镜（STM）和密度泛函理论（DFT）计算研究了丙烯腈在Si(111)-7×7上的共价键合。表面物种中C[双键]C[双键]N基团的特征振动模式和电子结构的观察表明，丙烯腈末端的C和N原子与相邻的吸附原子-静止原子对之间发生了类似[4 + 2]的环加成反应，这与DFT计算的预测一致。STM研究进一步表明，丙烯腈优先结合在Si(111)-7×7晶胞缺陷半部的中心吸附原子位点上。
