ja1c12618_si_001.pdf (1.33 MB)
Aza-Triangulene: On-Surface Synthesis and Electronic and Magnetic Properties
journal contribution
posted on 2022-03-07, 14:12 authored by Tao Wang, Alejandro Berdonces-Layunta, Niklas Friedrich, Manuel Vilas-Varela, Jan Patrick Calupitan, Jose Ignacio Pascual, Diego Peña, David Casanova, Martina Corso, Dimas G. de OteyzaNitrogen
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.
History
Usage metrics
Categories
Keywords
scanning tunneling microscopyscanning probe affordednew hydrocarbon structuresdifferent kondo resonancesdensity functional theoryatomic hydrogen followedpositively charged azaincluding reactive opendifferent metal surfaces111 ), azafinal azathermal annealingtarget productsubstituted precursorsstudy revealsshell moleculesshell characterreducing ketonemagnetic statecalculated counterparts111 ).