Covalent C–N Bond Formation through a Surface Catalyzed Thermal Cyclodehydrogenation

• Published in: Journal of the American Chemical Society Vol. 142; no. 8; pp. 3696 - 3700
• Main Authors: Piskun, Ilya, Blackwell, Raymond, Jornet-Somoza, Joaquim, Zhao, Fangzhou, Rubio, Angel, Louie, Steven G, Fischer, Felix R
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 26.02.2020; Amer Chemical Soc
• Subjects: catalytic activity; chemical bonding; Chemistry; Chemistry, Multidisciplinary; density functional theory; gold; Physical Sciences; polycyclic aromatic hydrocarbons; quinoxalines; scanning probe microscopy; Science & Technology; silver; spectroscopy; QUASI-PARTICLE; GAP
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.9b13507

The integration of substitutional dopants at predetermined positions along the hexagonal lattice of graphene-derived polycyclic aromatic hydrocarbons is a critical tool in the design of functional electronic materials. Here, we report the unusually mild thermally induced oxidative cyclodehydrogenation of dianthryl pyrazino­[2,3-g]­quinoxalines to form the four covalent C–N bonds in tetraazateranthene on Au(111) and Ag(111) surfaces. Bond-resolved scanning probe microscopy, differential conductance spectroscopy, along with first-principles calculations unambiguously confirm the structural assignment. Detailed mechanistic analysis based on ab initio density functional theory calculations reveals a stepwise mechanism featuring a rate determining barrier of only ΔE ⧧ = 0.6 eV, consistent with the experimentally observed reaction conditions.