Self-assembled monolayers of alkoxy-substituted octadehydrodibenzo[12]annulenes on a graphite surface: attempts at peri-benzopolyacene formation by on-surface polymerization.
Self-assembled monolayers of alkoxy-substituted octadehydrodibenzo[12]annulenes on a graphite surface: attempts at peri-benzopolyacene formation by on-surface polymerization.
复制标题
DOI：
10.1002/chem.201000711
复制
发表时间：
2010-07
期刊：
影响因子：
--
通讯作者：
Kazukuni Tahara;Koji Inukai;Noritaka Hara;Charles A. Johnson;M. Haley;Y. Tobe
中科院分区：
文献类型：
--
作者：
Kazukuni Tahara;Koji Inukai;Noritaka Hara;Charles A. Johnson;M. Haley;Y. Tobe
利用扫描隧道显微镜（STM）研究了一系列具有丁二炔键的四烷氧基取代八脱氢二苯并[12]轮烯（DBA）衍生物1c-g在1，2，4-三氯苯（TCB）或1-苯基辛烷/石墨界面上的自组装膜.本研究的目的不仅是调查二维（2D）单分子膜的结构变化，但也评估的可能性，通过在表面上的二维控制聚合的peri-benzopolyacene形成。其结果是，形成三种结构，多孔，线性和层状结构，观察到通过改变烷基链的长度和溶质浓度。所有的化合物都能观察到多层层状结构的形成。分子网络的选择基本上归因于单位面积上的分子间相互作用和分子-基质相互作用以及网络密度。一维线性结构的选择性出现归因于衬底晶格和覆盖层晶格之间的良好外延配准匹配。即使在片层结构中的DBA的二炔属单元之间的最近原子间距离（约0.6 nm）比局部化学聚合所需的典型距离略大，但研究了对外部刺激（来自STM尖端的电子脉冲照射和UV照射）的反应性。不幸的是，没有观察到DBA在表面上聚合的证据。本研究结果表明，有必要进一步设计一个合适的系统，结构新颖的共轭聚合物，这是难以制备的表面上的建设。
Self-assembled monolayers of a series of tetraalkoxy-substituted octadehydrodibenzo[12]annulene (DBA) derivatives 1c-g possessing butadiyne linkages were studied at the 1,2,4-trichlorobenzene (TCB) or 1-phenyloctane/graphite interface by scanning tunneling microscopy (STM). The purpose of this research is not only to investigate the structural variation of two-dimensional (2D) monolayers, but also to assess a possibility for peri-benzopolyacene formation by two-dimensionally controlled polymerization on a surface. As a result, the formation of three structures, porous, linear, and lamella structures, were observed by changing the alkyl chain length and the solute concentration. The formation of multilayers of the lamella structure was often observed for all compounds. The selection of molecular networks is basically ascribed to intermolecular and molecule-substrate interactions per unit area and network density. The selective appearance of the linear structure of 1d is attributed to favorable epitaxial registry matching between the substrate lattice and the overlayer lattice. Even though the closest interatomic distance between the diacetylenic units of the DBAs in the lamella structure (approximately 0.6 nm) is slightly larger compared to the typical distances necessary for topochemical polymerization, the reactivity toward external stimuli (electronic-pulse irradiation from an STM tip and UV irradiation) was investigated. Unfortunately, no evidence for polymerization of the DBAs on the surface was observed. The present results indicate the necessity for further designing a suitable system for the on-surface construction of structurally novel conjugated polymers, which are otherwise difficult to prepare.