Preservation of electronic properties of double-decker complexes on metallic supports.

Single-molecule magnets based on lanthanide double-deckers are attracting significant attention due to their unrivaled single-ion anisotropy. To exploit their fascinating electronic and magnetic properties in devices for information storage or spin transport, studies on the preservation or variation of electronic and magnetic functionalities upon adsorption on surfaces are necessary. Herein, we introduced a comprehensive scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) surface science study, complemented by density functional theory (DFT) simulations, of a recently synthesized single-molecule magnet based on porphyrazine deckers, conveniently equipped with ethyl moieties to make them soluble and sublimable. We demonstrated that the double-decker species were intactly adsorbed on Au(111), Ag(111), and Cu(111) in a flat-on fashion and self-assembled in hexagonal close-packed layers. Systematic multi- and monolayer XPS was performed on the surface-confined species, confirming the preservation of the electronic properties of the ligands and the lanthanide center upon adsorption.

Lanthanide-porphyrin species as Kondo irreversible switches through tip-induced coordination chemistry.

Metallosupramolecular chemical protocols are applied to in situ design dysprosium porphyrin complexes on Au(111) by sequential deposition of 2H-4FTPP species and Dy, resulting in the production of premetallated Dy-2H-4FTPP, partially metallated Dy-1H-4FTPP and fully metallated Dy-0H-4FTPP complexes, as determined by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. A zero bias resonance is found in the Dy-2H-4FTPP species which, upon study of its spatial distribution and behavior with temperature, is assigned to a Kondo resonance resulting from an unpaired spin in the molecular backbone, featuring a Kondo temperature (TK) of ≈ 21 K. Notably, the Kondo resonance can be switched off by removing one hydrogen atom of the macrocycle through tip-induced voltage pulses with submolecular precision. The species with this Kondo resonance can be laterally manipulated illustrating the potential to assemble artificial Kondo lattices. Our study demonstrates that the pre-metallation of macrocycles by lanthanides and their controlled manipulation is a novel strategy to engineer in situ tunable Kondo nanoarchitectures, enhancing the potential of coordination chemistry for spintronics.

Dysprosium-carboxylate nanomeshes with tunable cavity size and assembly motif through ionic interactions.

We report the design of dysprosium directed metallo-supramolecular architectures on a pristine Cu(111) surface. By an appropriate selection of the ditopic molecular linkers equipped with terminal carboxylic groups (TPA, PDA and TDA species), we create reticular and mononuclear metal-organic nanomeshes of tunable internodal distance, which are stabilized by eight-fold DyO interactions. A thermal annealing treatment for the reticular Dy:TDA architecture gives rise to an unprecedented quasi-hexagonal nanostructure based on dinuclear Dy clusters, exhibiting a unique six-fold DyO bonding motif. All metallo-supramolecular architectures are stable at room temperature. Our results open new avenues for the engineering of supramolecular architectures on surfaces incorporating f-block elements forming thermally robust nanoarchitectures through ionic bonds.