Heavy-Metal Based Supramolecular Coordination Structures Self-Assembled on Metal Surfaces

Abstract

Two-dimensional (2D) metal–organicframeworks (MOFs) self-assembledat solid-vacuum interfaces have attracted extensive attentions in last decade, owing to their unique chemical and physical properties, for example, heterogeneous catalysis, molecular magnetism, and selective host-guest binding. However, in contrast tothe abundantly reported transition metal coordinated MOFs, MOFs incorporating heavy metals such as p-block or f-block metals are rarely reported. 2D-MOFs incorporating heavy metals such as Pb have been theoretically predicted to exhibit non-trivial topological phases originating from strong spin orbital coupling (SOC) effect.This prediction hints that the Pb-coordinated 2D metal–organic structures may represent a new family of functional materials with appealing electronic and spintronic properties. Experimental realization of these predicated structures is therefore highly desirable. Lanthanide (Ln) based 2D-MOFs exhibit versatile morphologies, owing to the flexible coordination chemistry of Lnions. In this regard, 2D-MOFs involved Ln elementscan be attractive due to high thermal stability, tunable pore size, chemical sensing and potential application for heterogeneous catalysis. In this thesis, we focused on the rational design andfabrication of 2D-MOFs containingheavy metals, i.e., Pb and rare earthmetal-Eu on noblemetal substrates. We usedscanning tunneling microscopy (STM) to investigate the structures and self-assembly mechanism of these systems at a single-molecular level.