Aza-Triangulene: On-Surface Synthesis and Electronic and Magnetic Properties.
Tao WangAlejandro Berdonces-LayuntaNiklas FriedrichManuel Vilas-VarelaJan Patrick Dela Cruz CalupitanJosé Ignacio PascualDiego PeñaDavid CasanovaMartina CorsoDimas G de OteyzaPublished in: Journal of the American Chemical Society (2022)
Nitrogen heteroatom doping into a triangulene molecule allows tuning its magnetic state. However, the synthesis of the nitrogen-doped triangulene (aza-triangulene) has been challenging. Herein, we report the successful synthesis of aza-triangulene on the Au(111) and Ag(111) surfaces, along with their characterizations by scanning tunneling microscopy and spectroscopy in combination with density functional theory (DFT) calculations. Aza-triangulenes were obtained by reducing ketone-substituted precursors. Exposure to atomic hydrogen followed by thermal annealing and, when necessary, manipulations with the scanning probe afforded the target product. We demonstrate that on Au(111), aza-triangulene donates an electron to the substrate and exhibits an open-shell triplet ground state. This is derived from the different Kondo resonances of the final aza-triangulene product and a series of intermediates on Au(111). Experimentally mapped molecular orbitals match with DFT-calculated counterparts for a positively charged aza-triangulene. In contrast, aza-triangulene on Ag(111) receives an extra electron from the substrate and displays a closed-shell character. Our study reveals the electronic properties of aza-triangulene on different metal surfaces and offers an approach for the fabrication of new hydrocarbon structures, including reactive open-shell molecules.
Keyphrases
- density functional theory
- high resolution
- molecular dynamics
- sensitive detection
- electron microscopy
- single molecule
- quantum dots
- molecular docking
- magnetic resonance
- reduced graphene oxide
- magnetic resonance imaging
- gold nanoparticles
- escherichia coli
- minimally invasive
- computed tomography
- mass spectrometry
- highly efficient
- cystic fibrosis
- molecularly imprinted
- living cells
- candida albicans