Low-coordinate mononuclear lanthanide complexes as molecular nanomagnets

Chemical andin silicotuning of the magnetisation reversal barrier in pentagonal bipyramidal Dy(iii) single-ion magnets

“…This methodology has a proven track record to rationalize, and also predict at times, a reliable mechanism of magnetic relaxation. 12,13,19,20 The eight Kramers Doublets (KDs), corresponding to the 6 H 15/2 state, span within energy ranges of 882.1 cm À1 and 919.0 cm À1 , respectively for complexes 1 and 2. For both complexes, m J = AE15/2 is the ground state with m J = AE13/2 as the first excited state and m J = AE1/2 as the second-excited state.…”

“…Notably, the non-axial term (B q k , where q a 0 and k = 2, 4, and 6) to the axial term (B q k , where q = 0 and k = 2, 4, and 6) ratio is found to be smaller for complex 2 compared to 1, confirming the lower operational QTM and the larger U cal value for 2 compared to 1 (Table S7, ESI †). 20 In an attempt to evaluate how strongly the U cal values are related to molecules/fragments in the secondary coordination sphere, we have created a number of different model systems by step-by-step elimination of each fragment to generate a series of model complexes (Fig. 4 and Fig.…”

Closing the Circle of the Lanthanide-Murexide Series: Single-Molecule Magnet Behavior and Near-Infrared Emission of the NdIII Derivative

“…The only examples of zero-field Nd-SMMs reported so far are based on complexes made of phosphonic diamide-or phosphine oxide-based ligands [49,50]. The extremely strong geometric constrain [51] imposed by the ligands around the Nd III ions imposes a highly symmetric D 5h pentagonal bipyramid environment (O 7 ) with the apical oxygen atoms from the phosphine groups closer of the Nd III ions than the five equatorial water molecules. This induces a suitable electrostatic surrounding of the Nd III ion that is an oblate ion [52].…”

Propeller‐Shaped Fe4 and Fe3M Molecular Nanomagnets: A Journey from Crystals to Addressable Single Molecules

“…In the last twenty years the chemical research has been focused on two main goals: increasing the height of the anisotropy barrier and controlling the efficiency of underbarrier processes, which lead to undesired information loss , . The geometry of the coordination environment and the electronic structure of the metal ions are the parameters that have been mainly explored, with a pronounced shift of the interest from 3d to 4f ions . The latter can indeed exhibit large magnetic moments and unsurpassed magnetic anisotropy due to the unquenched orbital momentum.…”