Mechanically Interlocked Molecular Rotors on Pb(100).

The mechanical coupling between molecules represents a promising route for the development of molecular machines. Constructing molecular gears requires easily rotatable and mutually interlocked pinions. Using scanning tunneling microscopy (STM), it is demonstrated that aluminum phthalocyanine (AlPc) molecules on Pb(100) exhibit these properties.

Spin-state switching of indium-phthalocyanine on Pb(100).

Indium(iii) phthalocyanine chloride deposited on Pb(100) is studied by scanning tunnelling spectroscopy at cryogenic temperatures. The Cl ions are dissociated and the remaining indium phthalocyanine (InPc) is observed in two states with the metal ion pointing to (↓) or away (↑) from the substrate. Isolated molecules and islands with a superstructure and a unit cell of four inequivalent molecules, namely one InPc↑ and three InPc↓ in different sites, are observed.

Large Orbital Moment and Dynamical Jahn-Teller Effect of AlCl-Phthalocyanine on Cu(100).

Submonolayer amounts of chloroaluminum-phthalocyanine on Cu(100) were studied with scanning tunneling spectroscopy. The molecule can be prepared in a fourfold symmetric state whose conductance spectrum exhibits a zero-bias feature similar to a Kondo resonance. In magnetic fields, however, this resonance splits far more than expected from the spin of a single electron.

Spin-State Switching of Spin-Crossover Complexes on Cu(111) Evidenced by Spin-Flip Spectroscopy.

Spin-crossover compounds can be switched between two stable states with different magnetic moments, conformations, electronic, and optical properties, which opens appealing perspectives for technological applications including miniaturization down to the scale of single molecules. Although control of the spin states is crucial their direct identification is challenging in single-molecule experiments. Here we investigate the spin-crossover complex [Fe(HB(1,2,4-triazol-1-yl))] on a Cu(111) surface with scanning tunneling microscopy and density functional theory calculations.