Structural Transformation of 2,7-Dibromopyrene on Au(111) Mediated by Halogen-Bonding Motifs
Structural Transformation of 2,7-Dibromopyrene on Au(111) Mediated by Halogen-Bonding Motifs
复制标题
卤素键介导的 2, 7-二溴芘在 Au (111) 上的结构转变
DOI：
10.1002/cphc.201900259
复制
发表时间：
2019-09-17
期刊：
影响因子：
2.9
通讯作者：
Song, Fei
中科院分区：
文献类型：
--
作者：
Hu, Jinbang;Shen, Kongchao;Song, Fei
基本了解的键合图案，精心介导的超分子纳米结构的形成是必不可少的稳定的人工有机建筑的合理设计。本文采用扫描隧道显微镜结合X射线光电子能谱和密度泛函理论计算研究了2，7-二溴芘（Br 2 Py）在Au（111）表面吸附配合物的结构转变.在自组装的初始阶段，有序的超分子结构以分子间卤素键的平衡方式形成，而Au（111）重构仍然相当明显。随后的热退火促进脱卤和表面乌尔曼耦合，并因此构建聚合的低聚物。有趣的是，这样的聚合链仍然是稳定介导的卤素键合基序通过解离的Br原子，被揭示为被吸附在Au（111）的桥位上，而卤素键的数量显着增加，从自组装到Ullmann偶联聚合，表明卤素键合基序显着地有助于扩展的一维聚合物。
Fundamental understanding of the bonding motifs that elaborately mediate the formation of supramolecular nanostructures is essential for the rational design of stable artificial organic architectures. Herein, the structural transformation of the adsorption complex of 2, 7-dibromopyrene (Br2Py) on the Au(111) surface has been investigated by scanning tunnelling microscopy combined with X-ray photoemission spectroscopy and density function theory calculations. In the initial stage of self-assembly, well ordered patterns are formed in the manner of extended supramolecular structures balanced by intermolecular halogen bonding motifs, whilst the Au(111) reconstruction is still fairly visible. Subsequent thermal annealing promotes the dehalogenation and on-surface Ullmann coupling, and polymerized oligomers are consequently constructed. Interestingly, such polymerized chains are still stably mediated by the halogen bonding motif via dissociated Br atoms which are revealed to be absorbed on the bridge site of Au(111), while the number of halogen bonds increases significantly from self-assembly to Ullmann coupling polymerization, indicating that the halogen bonding motif contributes significantly to the extended one-dimensional polymers.