Using a Radical Straitjacket to Enforce an Ultrashort Dy-Dy Distance and Thus Enhance Dipolar Interactions in a
Anthony B Carter1,2, Jonas Braun1,3,4, Tilmann Bodenstein3,5,6
1Institute for Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, Karlsruhe 76131, Germany.
Abstract:
We present three air-stable radical-containing compounds, [MIII2(phsq)4(NO3)2(MeOH)2]·2MeOH (M = Dy (1), Y (2), Gd (3); Hphsq = 9,10-phenanthrenesemiquinone), in which strong intramolecular inter-radical interactions force two lanthanide ions into close proximity and isolate them from the lattice. Magnetic measurements on (1) showed it to be an SMM with maxima in the ac susceptibility up to 18 K (1000 Hz). Modeling the magnetic data using three different analytical approaches reveals the absence of zero-field quantum tunneling of magnetization (ZFQTM) as a relaxation pathway. This is a result of significant internal magnetic fields identified by ab initio calculations that appear to quench the ZFQTM. This can be verified from measurements performed on an Y-doped sample (1a), which show that strong ZFQTM is present in the DyY analogue.
Related Concept Videos
Radical Reactivity: Intramolecular vs Intermolecular
Molecular Geometry and Dipole Moments
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
Intermolecular Forces
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Radical Reactivity: Steric Effects
Along with electronic...


