Magnetism engineering of nanographene: An enrichment strategy by co-depositing diverse precursors on Au(111)

The magnetism of nanographene is dominated by the structure of its carbon skeleton. However, the magnetism engineering of nanographene is hindered due to finite precursors. Here, we demonstrate an ingenious synthetic strategy to engineer the magnetism of nanographene through hetero-coupling two precursors on Au(111) surface. Bond-resolved scanning tunneling microscopy and spectroscopy results show that two homo-coupled products host a closed-shell structure, while the products with five membered ring defects perform as an open-shell one with the total spin number of 1/2, confirmed by spin-polarized density functional theory calculations. While two hetero precursors on Au(111) substrate, the hetero-coupled products both perform as the magnetic structure with total spin quantum numbers of 1/2 and 1, resulting from carbon skeleton transformations. Our work provides an effective way to engineer the magnetism of nanographene by enriching the magnetic products simultaneous, which could be extended into other controllable magnetic nanographene instruction. We demonstrate an efficient synthetic strategy to engineer and enrich the magnetism of nanographene through hetero-coupling two precursors on Au(111) surface.