Morphological Change of Molecular Assemblies through On-Surface Chemical Reaction

Fabrication of molecular assemblies by arranging molecules through on-surface chemical reactions is an attractive way of functionalizing nanosheets chemically. Here, we study morphological changes of organometallic assemblies on a graphene oxide surface by controlling the formation of covalent bonds through on-surface chemical reactions with and without coupling agents. The difference in surface morphology originates from the different crystal growths of molecules diffusing on the surface, relating to the formation of covalent immobilization between the molecule and the surface. The molecules forming the assemblies have individual spins acquired by charge transfer between the molecule and the surface. The size and distribution of the assemblies on the surface produce morphology-related magnetism among the weakly interacting molecular spins. The present approach based on arranging simple molecules through on-surface chemical reactions provides new insights into molecular magnetism.