Slow-spin relaxation of a low-spin S = 1/2 Fe^III carborane complex

Abstract

Slow-spin relaxation through Raman and direct mechanisms of a low-spin S = 1/2 FeIII carborane complex with the metal directly coordinated to the carborane ligand.

Effect of the Transition Metal Ions on the Single-Molecule Magnet Properties in a Family of Air-Stable 3d–4f Ion-Pair Compounds with Pentagonal Bipyramidal Ln(III) Ions

“…The dc magnetic susceptibility data of compounds 1–5 were measured under an external field of 1 kOe and in the temperature range of 2–300 K (Figure and Figure S4). The χ M T value of 0.69 cm 3 K mol –1 at 300 K for 1 is close to the expected value of 0.54–0.68 cm 3 K mol –1 for one magnetically isolated low-spin Fe III ion with a significant orbital contribution ([Fe III ] LS , S = 1 / 2 , g = 2.1) . The slow decrease in the χ M T value (0.51 cm 3 K mol –1 at 2 K) with a decrease in temperature can be attributed to the orbital contribution of the free [Fe III ] LS ion under the circumstances that the minimum intermolecular Fe III ···Fe III separation of 8.8413(5) Å is relatively large.…”

Spin‐Phonon Coupling and Slow‐Magnetic Relaxation in Pristine Ferrocenium

“…The different interelectronic repulsion of such orbitals is enough to compensate their energy difference, resulting in an anomalous occupation. According to Equation (1), the low‐energy excitation, from the doubly‐occupied d x 2 ‐ y 2 to singly‐occupied d xy orbital, results in a large positive g z contribution, as the one found in the CASPT2/NEVPT2 calculations, agreeing with the easy‐axis anisotropy found experimentally and showing a similar behaviour as substituted ferrocenium and Fe III carborane compounds [28,64] . Furthermore, the ground state has a strong multireference character after the inclusion of spin‐orbit coupling.…”

“…According to Equation (1), the low‐energy excitation, from the doubly‐occupied d x 2 ‐ y 2 to singly‐occupied d xy orbital, results in a large positive g z contribution, as the one found in the CASPT2/NEVPT2 calculations, agreeing with the easy‐axis anisotropy found experimentally and showing a similar behaviour as substituted ferrocenium and Fe III carborane compounds. [ 28 , 64 ] Furthermore, the ground state has a strong multireference character after the inclusion of spin‐orbit coupling. At CASSCF level, the two involved electronic configurations (d x 2 ‐ y 2 2 d xy 1 d z 2 2 and d xy 2 d x 2 ‐ y 2 1 d z 2 2 ) have a weight each close to one in the first two states.…”

The Mössbauer effect using 57Fe-ferrabisdicarbollide ([o-57FESAN]−): a glance into the potential of a low-dose approach for glioblastoma radiotherapy

“…As the anionic [ o -FESAN] − complex is an S = 1/2 species, to assess the magnetic properties of the paramagnetic Na[ o -FESAN], EPR measurements on Na[ o -FESAN] were also run in the solid state and in acetone solution. The EPR spectra of the recently reported low-spin [NMe 4 ][ o -FESAN] salt 37 and ferrocene were also run for comparison.…”