Resolving the Unpaired‐Electron Orbital Distribution in a Stable Organic Radical by Kondo Resonance Mapping

Abstract

The adsorption geometry and the electronic structure of aB latter radical derivative on ag old surface were investigated by ac ombination of high-resolution noncontact atomic force microscopya nd scanning tunneling microscopy. While the hybridization with the substrate hinders direct access to the molecular states,w es howt hat the unpaired-electron orbital can be probed with ngstrçm resolution by mapping the spatial distribution of the Kondo resonance.T he Blatter derivative features ap eculiar delocalization of the unpairedelectron orbital over some but not all moieties of the molecule, such that the Kondo signature can be related to the spatial fingerprint of the orbital. We observe ad irect correspondence between these two quantities,i ncluding ap ronounced nodal plane structure.F inally,w ed emonstrate that the spatial signature of the Kondo resonance also persists upon noncovalent dimerization of molecules.

Recent advances of stable Blatter radicals: synthesis, properties and applications

“…7d and e). 53 The spatial distribution of the Kondo resonance was explored and obtained the spatial distribution of the singly occupied molecular orbitals (SOMO), and even showed the node plane structure of the corresponding orbitals. These results demonstrated that the Kondo resonance was state-selective when entering the molecular state responsible for spin-metal coupling, and thus achieved enhanced imaging resolution despite orbital and metal substrate hybridization.…”

“…19,20,22,23,25,[61][62][63][64][65][66] Open-shell molecules already show some potential in organic based devices. [19][20][21]52,53 However, the issue of synthetic difficulty and stability in radical containing molecules hold it back for further development in electronic applications. Therefore, Blatter radicals are promising candidates to be built in devices.…”

Design Considerations for Oligo(p-Phenyleneethynylene) Organic Radicals in Molecular Junctions

“…Molecules display particularly rich behavior when they feature unpaired spins, as present in many transition metal complexes and in organic radicals [20][21][22][23][24][25][26][27][28][29][30]. In the past few years, such molecules have been more and more in the focus of single-molecule break junction experiments with nonmagnetic electrodes, and in particular their response to magnetic fields [11,31], Kondo properties [32][33][34][35] and shot noise resulting from spin correlations [36,37] have been studied. Radicals adsorbed on graphene were also found to enhance the conductance and the Seebeck coefficient of graphene nanoconstrictions based on first-principles simulations [38].…”

How Plausible Is Getting Ferromagnetic Interactions by Coupling Blatter’s Radical via Its Fused Benzene Ring?

“…14 Several recent studies have also examined the stability of Blatter's radicals when interfaced with metallic substrates and conducting electrodes. 15,16 The radical has also found extensive applications in transition metal-radical complexes, 17 optical properties including photocyclization 18 and in context of controlled polymerization. 19 With a biggest challenge to synthesize room temperature stable organic diradicals, Rajca et al successfully coupled the stable nitronyl nitroxide (NN) as well as imino nitroxide (IN) radical with the Blatter's radical to obtain hybrid diradicals that exhibit reasonably strong ferromagnetic exchange interactions.…”