Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
Nanotechnology. 2010 Jul 30;21(30):305703. doi: 10.1088/0957-4484/21/30/305703. Epub 2010 Jul 6.
In this work we combine organic molecules of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) with iron atoms on an Au (111) substrate in ultra-high vacuum conditions at different temperatures. By means of scanning tunnelling microscopy (STM) we study the formation of stable 2D metal-organic structures. We show that at certain growth conditions (temperature, time and coverage) stable 'ladder-like' nanostructures are obtained. These are the result of connecting together two metal-organic chains through PTCDA molecules placed perpendicularly, as rungs of a ladder. These structures, stable up to 450 K, can be extended in a 2D layer covering the entire surface and presenting different rotation domains. STM images at both polarities show a contrast reversal between the two molecules at the unit cell. By means of density functional theory (DFT) calculations, we confirm the stability of these structures and that their molecular orbitals are placed separately at the different molecules.
在这项工作中，我们在超高真空条件下将 3,4,9,10-苝四羧酸二酐（PTCDA）的有机分子与金（111）基底上的铁原子结合在一起，并在不同温度下进行。通过扫描隧道显微镜（STM），我们研究了稳定的二维金属有机结构的形成。我们表明，在某些生长条件（温度、时间和覆盖率）下，会获得稳定的“梯形”纳米结构。这些结构是通过将两个通过垂直放置的 PTCDA 分子连接在一起形成的，就像梯子的梯级一样。这些结构在高达 450 K 的温度下稳定，可以在覆盖整个表面的二维层中扩展，并呈现出不同的旋转畴。在两种极性下的 STM 图像都显示了单元晶格中两个分子之间的对比度反转。通过密度泛函理论（DFT）计算，我们证实了这些结构的稳定性，并且它们的分子轨道分别位于不同的分子上。
