基于卤键的谢尔宾斯基三角分形自组装的模拟研究

摘要

采用粗粒化的格点模型和蒙特卡罗方法,对在三角网格表面通过自组装形成了谢尔宾斯基三角分形结构进行了模拟研究.研究发现,对称和非对称基元都可以自发形成谢尔宾斯基三角分形结构,然而对于非对称分子的对映异构体的混合物,由于大量的具有竞争性的三元节点的出现,很难形成更高阶的分形结构.我们还发现,分形结构在表面覆盖度低的时候才会出现,而且对温度较为敏感.此外,为了检测是否可以通过分子设计来控制组装途径和结果,我们通过使用与组装基元不同的模板来实现对自组装过程和结果的控制.其中,模板作为“催组剂”诱导自组装,但不会出现在最终的组装结构中.%In this study,a coarse-grained lattice Monte Carlo model was used to investigate the formation of Sierpifiski triangle (ST) fractals through self-assembly on a triangular lattice surface.In the simulations,both symmetric and asymmetric molecular building blocks can spontaneously form ST fractal patterns,although the mixture of enantiomers of asymmetric molecule is more difficult to self-organize into ST of a high order owing to the presence of a large variety of competing three-membered nodes.The formation of ST fractals is favored at low surface coverage and is sensitive to temperature.Furthermore,to test whether the assembly pathway and outcome could be controlled by molecular design,we guided the self-assembly process forming ST fractal into the otherwise disfavored self-assembled structures using templates different from the assembling molecules.The templates are designed to act as "catassemblers" that initiate the self-assembling but are excluded from the final assembled structure.