Institut für Physikalische Chemie, Fachbereich Chemie, Johannes Gutenberg-Universität Mainz, Jakob-Welder-Weg 11, 55099 Mainz, Germany.
Phys Chem Chem Phys. 2012 May 14;14(18):6544-8. doi: 10.1039/c2cp40172j. Epub 2012 Mar 28.
We report the formation of extended molecular layers of C(60) molecules on a dielectric surface at room temperature. In sharp contrast to previous C(60) adsorption studies on prototypical ionic crystal surfaces, a wetting layer is obtained when choosing the calcite (CaCO(3))(10 ̅14) surface as a substrate. Non-contact atomic force microscopy data reveal an excellent match of the hexagonal lattice of the molecular layer with the unit cell dimension of CaCO(3)(10 ̅14) in the [01 ̅10] direction, while a lattice mismatch along the [ ̅4 ̅261] direction results in a large-scale moiré modulation. Overall, a (2 × 15) wetting layer is obtained. The distinct difference observed microscopically upon C(60) adsorption on CaCO(3)(10 ̅14) compared to other dielectric surfaces is explained by a macroscopic picture based on surface energies. Our example demonstrates that this simple surface-energy based approach can provide a valuable estimate for choosing molecule-insulator systems suitable for molecular self-assembly at room temperature.
我们在室温下报告了 C(60)分子在介电表面上形成扩展的分子层。与之前在典型离子晶体表面上进行的 C(60)吸附研究形成鲜明对比的是，当选择方解石 (CaCO(3))(10 ̅14)表面作为基板时，会获得一个润湿层。非接触原子力显微镜数据显示，分子层的六边形晶格与 CaCO(3)(10 ̅14)在 [01 ̅10]方向上的单位晶格尺寸非常匹配，而在 [ ̅4 ̅261]方向上的晶格失配导致了大规模的莫尔调制。总的来说，获得了一个 (2 × 15)的润湿层。与其他介电表面相比，在 CaCO(3)(10 ̅14)上吸附 C(60)时微观上观察到的明显差异，可以用基于表面能的宏观图像来解释。我们的例子表明，这种简单的基于表面能的方法可以为选择适合室温下分子自组装的分子-绝缘体系统提供有价值的估计。
