Boukari Khaoula, Duverger Eric, Stephan Régis, Hanf Marie-Christine, Sonnet Philippe
IS2M UMR CNRS 7361 - UHA, 15 rue Jean Starcky, 68057 Mulhouse, France.
Phys Chem Chem Phys. 2014 Jul 28;16(28):14722-9. doi: 10.1039/c4cp01677g.
C60 fullerene assemblies on surfaces have attracted considerable attention because of their remarkable electronic properties. Now because of the competition between the molecules-substrate and the molecule-molecule interactions, an ordered C60 array is rather difficult to obtain on silicon surfaces. Here we present density functional theory simulations on C60 molecules deposited on a TBB (1,3,5-tri(1'-bromophenyl)benzene) monolayer lying on the Si(111)-boron surface (denoted SiB). The C60 molecules are located in the nanopores formed by the TBB network. Adsorption energy calculations show that the SiB surface governs the C60 vertical position, whereas the TBB network imposes the C60 lateral position, and stabilizes the molecule as well. The low charge density between the C60 and the SiB substrate on one hand, and on the other hand between the C60 and the TBB molecules, indicates that no covalent bond is formed between the C60 and its environment. However, according to charge density differences, a drastic charge reorganisation takes place between the Si adatoms and the C60 molecule, but also between the C60 and the surrounding TBB molecules. Finally, calculations show that a C60 array sandwiched between two TBB molecular layers is stable, which opens up the way to the growth of 3D supramolecular networks.
表面上的C60富勒烯组装体因其卓越的电子特性而备受关注。由于分子-衬底和分子-分子相互作用之间的竞争，在硅表面很难获得有序的C60阵列。在此，我们展示了关于沉积在位于Si(111)-硼表面（记为SiB）的1,3,5-三(1'-溴苯基)苯（TBB）单层上的C60分子的密度泛函理论模拟。C60分子位于由TBB网络形成的纳米孔中。吸附能计算表明，SiB表面决定C60的垂直位置，而TBB网络决定C60的横向位置，并且也使分子稳定。一方面，C60与SiB衬底之间，另一方面，C60与TBB分子之间的低电荷密度表明，C60与其周围环境之间没有形成共价键。然而，根据电荷密度差异，在硅吸附原子与C60分子之间，而且在C60与周围的TBB分子之间发生了剧烈的电荷重新组织。最后，计算表明夹在两个TBB分子层之间的C60阵列是稳定的，这为三维超分子网络的生长开辟了道路。
