Synthesis and characterization of a -extended Clar's goblet
arXiv:2505.03289 · doi:10.1021/jacs.5c07588
Abstract
Concealed non-Kekulé polybenzenoid hydrocarbons have no sublattice imbalance yet cannot be assigned a classical Kekulé structure, leading to an open-shell ground state with potential application in organic spintronics. They constitute an exceedingly small fraction of the total number of polybenzenoid hydrocarbons that can be constructed for a given number of benzenoid rings, and their synthesis remains challenging. The archetype of such a system is Clar's goblet (CH), a diradical proposed by Erich Clar in 1972 and recently synthesized on a Au(111) surface. Here, we report the synthesis of a pi-extended Clar's goblet (CH), a tetraradical concealed non-Kekulé polybenzenoid hydrocarbon, by a combined in-solution and on-surface synthetic approach. By means of low-temperature scanning tunneling microscopy and atomic force microscopy, we characterized individual molecules adsorbed on a Cu(111) surface. We provide insights into the electronic properties of this elusive molecule, including the many-body nature of its ground and excited states, by mean-field and multiconfigurational quantum chemistry calculations.
arXiv commentManuscript contains 6 pages and 4 figures; supporting information contains 17 pages and 17 figures
References in corpus (7)
- Topological Frustration in Graphene Nanoflakes: Magnetic Order and Spin Logic Devices
- Giant magnetic exchange coupling in rhombus-shaped nanographenes with zigzag periphery
- Uncovering the Triplet Ground State of Triangular Graphene Nanoflakes Engineered with Atomic Precision on a Metal Surface
- Aza-Triangulene: On-Surface Synthesis, Electronic and Magnetic Properties
- Direct observation of the magnetic ground state of the two smallest triangular nanographenes
- Role of Kekulé and Non-Kekulé Structures in the Radical Character of Alternant Polycyclic Aromatic Hydrocarbons: A TAO-DFT Study
- On-Surface Synthesis and Characterization of a High-Spin Aza-[5]-Triangulene