Mishra, ShantanuShantanuMishraXu, KunKunXuEimre, KristjanKristjanEimreKomber, HartmutHartmutKomberMa, JiJiMaPignedoli, Carlo A.Carlo A.PignedoliFasel, RomanRomanFaselFeng, XinliangXinliangFengRuffieux, PascalPascalRuffieux2024-10-092024-10-092021https://boris-portal.unibe.ch/handle/20.500.12422/67020Triangulene and its π-extended homologues constitute non-Kekulé polyradical frameworks with high-spin ground states, and are anticipated to be key components of organic spintronic devices. We report a combined in-solution and on-surface synthesis of the hitherto largest triangulene homologue, [7]triangulene (C78H24), consisting of twenty-eight benzenoid rings fused in a triangular fashion. We employ low-temperature scanning tunneling microscopy to confirm the chemical structure of individual molecules adsorbed on a Cu(111) surface. While neutral [7]triangulene in the gas phase is predicted to have an open-shell septet ground state; our scanning tunneling spectroscopy measurements, in combination with density functional theory calculations, reveal chemisorption of [7]triangulene on Cu(111) together with considerable charge transfer, resulting in a closed-shell state. Furthermore, substantial hybridization between the molecular orbitals of [7]triangulene is observed.en500 - Science::530 - Physics500 - Science::540 - Chemistryarticle10.48350/1648663344327010.1039/D0NR08181G