Two-dimensional (2D) metal–organic frameworks (MOFs) self-assembled at 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 to the 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...[ Read more ]

Two-dimensional (2D) metal–organic frameworks (MOFs) self-assembled at 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 to the 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 Ln ions. In this regard, 2D-MOFs involved Ln elements can 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 and fabrication of 2D-MOFs containing heavy metals, i.e., Pb and rare earth metal-Eu on noble metal substrates. We used scanning tunneling microscopy (STM) to investigate the structures and self-assembly mechanism of these systems at a single-molecular level.