【作者】 王涛； 范其瑭； 代景亚； 冯林； 朱俊发；

【Author】 Tao Wang;Qitang Fan;Jingya Dai;Lin Feng;Junfa Zhu;National Synchrotron Radiation Laboratory and Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China;

【机构】 中国科学技术大学国家同步辐射实验室和苏州纳米科技协同创新中心；

【摘要】 由于在制备抗癌药物等方面的巨大应用前景,过去三十年里,在溶液中选择性地合成顺式烯二炔得到广泛研究。本工作首次报道了在金属单晶表面上合成出高产率的顺式烯二炔,并利用超高真空扫描隧道显微镜(STM)和光电子能谱(XPS)技术研究了其形成过程和机理。93 K下,在Ag(111)表面沉积1,1’联苯,4-溴-4-乙炔基-(BPBE)分子,前驱体分子通过溴溴卤键和炔基的相互作用,在表面上形成风车状的有序结构。当把Ag(111)单晶的温度提高到420 K后沉积BPBE分子,分子脱溴并形成产率高达90%的顺式烯二炔结构。通过与不含有溴原子的前驱体分子对照研究,发现溴原子在顺式烯二炔生成过程中扮演着重要的角色,由于溴氢的相互作用烯二炔分子堆积成岛,形成了较大的空间位阻,阻碍了炔基的进一步反应。更多还原

【Abstract】 Selective synthesis of cis-enediyne structures has been widely investigated in solution for last three decades because of its promising applications as potent anticancer agents. Here with the characterization of scanning tunneling microscopy(STM) and X-ray photo-electron spectroscopy(XPS) in ultra-high vacuum(UHV), we report for the first time the selective synthesis of cis-enediyne on a metal surface with a high yield. Vapor deposition of 1, 1’-Biphenyl, 4-bromo-4’-ethynyl-(BPBE) onto Ag(111) held at 93 K leads to the formation of windmill-like ordered structures, which are stabilized by fourfold Br…Br bond s and interactions of alkynyl groups between intact BPBE molecules. When the deposition of BPBE was performed at 420 K, debromination happens and cis-enediyne structure are formed with a yield of ~90%. Br atoms play a critical role on the process of selective synthesis of cis-enediyne, due to its ability to gather products into close-packed islands through Br…H bonds which results in the increasement of steric hindrance of further reactions.更多还原