Precise Structural Engineering and Finely-Tunable Properties of Two Dimensional Plasmonic Nanoparticle Assemblies SHIQIANQIAN 2018 This thesis introduces three model systems to precisely engineer the structure and finely tune properties of 2D plasmonic nanoassemblies. The first one demonstrated a new system with “one particle building blocks, different particle arrangements”; the second system showed nanoassemblies with “one original nanosheet, different generations of transformed nanosheets”; the last system represented “one system, different kinds of building blocks”. These systems allow us to have a better understanding of the structure and plasmonic properties relationship of nanoparticles, show us the possibility of manipulating building blocks in a precise manner, and introduce additional novel properties into 2D plasmonic systems.