INRS-EMT, Université du Québec, 1650 Boulevard Lionel-Boulet, Varennes, Quebec, Canada J3X 1S2.
J Am Chem Soc. 2009 Nov 25;131(46):16844-50. doi: 10.1021/ja906206g.
Scanning tunneling microscopy (STM) of monolayers comprising oligothiophene and fullerene molecular semiconductors reveals details of their molecular-scale phase separation and ordering with potential implications for the design of organic electronic devices, in particular future bulk heterojunction solar cells. Prochiral terthienobenzenetricarboxylic acid (TTBTA) self-assembles at the solution/graphite interface into either a porous chicken wire network linked by dimeric hydrogen bonding associations of COOH groups (R(2)(2) (8)) or a close-packed network linked in a novel hexameric hydrogen bonding motif (R(6)(6) (24)). Analysis of high-resolution STM images shows that the chicken wire phase is racemically mixed, whereas the close-packed phase is enantiomerically pure. The cavities of the chicken wire structure can efficiently host C60 molecules, which form ordered domains with either one, two, or three fullerenes per cavity. The observed monodisperse filling and long-range co-alignment of fullerenes is described in terms of a combination of an electrostatic effect and the commensurability between the graphite and molecular network, which leads to differentiation of otherwise identical adsorption sites in the pores.
扫描隧道显微镜（STM）对由寡聚噻吩和富勒烯分子半导体组成的单层的研究揭示了它们在分子尺度上的相分离和有序的细节，这对于设计有机电子器件，特别是未来的体异质结太阳能电池具有潜在的意义。手性三亚噻吩三羧酸（TTBTA）在溶液/石墨界面自组装成两种结构：一种是由 COOH 基团的二聚氢键连接的多孔鸡笼状网络（R(2)(2) (8)），另一种是由新颖的六聚氢键模式连接的密堆积网络（R(6)(6) (24)）。高分辨率 STM 图像分析表明，鸡笼相是外消旋混合的，而密堆积相是对映纯的。鸡笼结构的空腔可以有效地容纳 C60 分子，这些分子在每个空腔中形成具有一个、两个或三个富勒烯的有序域。观察到的富勒烯的单分散填充和长程共取向可以用静电效应和石墨与分子网络之间的协调性来描述，这导致了在孔隙中原本相同的吸附位的区分。
