Communication: Electrical rectification of C59N: The role of anchoring and doping sites

High-Resolution Photoelectron Imaging of Cryogenically-Cooled C59N- and (C59N)22- Azafullerene Anions

We report a photoelectron imaging study of cryogenically cooled C₅₉N^- and (C₅₉N)₂^2- anions produced from electrospray ionization. High-resolution photoelectron spectra are obtained for C₅₉N^- for the first time, allowing seven vibrational frequencies of the C₅₉N azafullerene to be measured. The electron affinity of C₅₉N is determined accurately to be 3.0150 ± 0.0007 eV. The observed vibrational features are understood on the basis of calculated frequencies and compared with those of C₆₀ and C₅₉HN. The photoelectron image of (C₅₉N)₂^2-, which has the same mass/charge ratio as C₅₉N^-, is also observed, allowing the second electron affinity of the (C₅₉N)₂ azafullerene dimer to be measured as 1.20 ± 0.05 eV. The intramolecular Coulomb repulsion of the (C₅₉N)₂^2- dianion is estimated to be 1.96 eV and is investigated theoretically using the electron density difference between (C₅₉N)₂^2- and (C₅₉N)₂.

Near-Perfect Spin Filtering and Negative Differential Resistance in an Fe(II)S Complex

Density functional theory and nonequilibrium Green's function calculations have been used to explore spin-resolved transport through the high-spin state of an iron(II)sulfur single molecular magnet. Our results show that this molecule exhibits near-perfect spin filtering, where the spin-filtering efficiency is above 99%, as well as significant negative differential resistance centered at a low bias voltage. The rise in the spin-up conductivity up to the bias voltage of 0.4 V is dominated by a conductive lowest unoccupied molecular orbital, and this is accompanied by a slight increase in the magnetic moment of the Fe atom. The subsequent drop in the spin-up conductivity is because the conductive channel moves to the highest occupied molecular orbital, which has a lower conductance contribution. This is accompanied by a drop in the magnetic moment of the Fe atom. These two exceptional properties, and the fact that the onset of negative differential resistance occurs at low bias voltage, suggests the potential of the molecule in nanoelectronic and nanospintronic applications.

Endohedral metallofullerenes, M@C60 (M = Ca, Na, Sr): selective adsorption and sensing of open-shell NOx gases

Based on density-functional theory and non-equilibrium Green's function calculations, we demonstrate that endohedral metallofullerenes (EMFs) are reactive to open-shell gases, and therefore have the potential application as selective open-shell gas sensors.