【作者】 查宝； 胡懿； 苗新蕊； 邓文礼；

【Author】 Bao Zha;Yi Hu;Xinrui Miao;Wenli Deng;College of Materials Science and Engineering, South China University of Technology;

【机构】 华南理工大学；

【摘要】 利用扫描隧道显微镜(STM)研究了π共轭的噻吩并菲衍生物(DDTDs)在不同浓度下辛苯和脂肪烃溶剂中的自组装单分子层膜。STM实验发现噻吩并菲衍生物的自组装结构展现出很强的溶剂效应。在辛苯/石墨界面,伴随着浓度降低时,自组装结构从四聚体向矩形的结构转变。当脂肪烃作为溶剂时,结果发现了自组装结构的多样性以及浓度效应:其中在低浓度时,和脂肪烃溶剂分子共吸附成条垄状结构;然而在高浓度时,更倾向于形成密堆积的结构。所有的自组装结构不仅是在范德华作用力,而且还在溴…溴和溴…氢作用力共同作用下形成的稳定结构。密度泛函理论(DFT)优化计算不同的结构基元,更深层次的揭示了自组装结构形成的机理。更多还原

【Abstract】 The π-conjugated thienophenanthrene derivatives(DDTDs) self-assembled monolayers in 1-phenyloctane and aliphatic solvents under different concentrations were investigated by scanning tunneling microscopy(STM). The STM results reveal that the self-assembled structures of the DDTDs are strongly solvent-dependent. At the 1-phenyloctane/graphite interface, the structural transformation of the monolayer from the tetramer phase to rectangle phase can be observed with the decrease of the concentration. When aliphatic hydrocarbon used as the solvent, the results show structural diversity and exhibit concentration effect. Lower solution concentration leads to a coadsorbed lamellar pattern with coadsorption of aliphatic solvent molecules, whereas the higher concentration favours the formation of a dense polymorphous structure. All ordered self-assembled adlayers critically depend on not only weak interchain van der Waals interactions, but the asymmetric bifurcated Br…Br and Br…H interactions. Density functional theory(DFT) calculations support to unravel different elementary structural units, which are useful tools to dissect and explain the formation mechanism.更多还原