Phosphine Oxide Coordinated Mononuclear LnIII (Ln= DyIII, ErIII) Single-Ion Magnet with Pseudo-Pentagonal Bipyramidal Geometry
Authors :- S Roy, B Li, EM Manohar, H Sharma, B Sarma, L Sun & S. Das.
Publication :- ChemPlusChem, Wiley, 2025
Two mononuclear lanthanide complexes, [(L)LnIII(Ph3PO)Cl]·CH3OH] [LnIII = Dy (1) and Er(2)], are isolated employing a pyridine-based ligand, [2,2′-{(1E, 1′E)-pyridine 2,6–diylbis(methaneylylidine}bis(azaneylylidine)diphenol] (H2L) and triphenylphosphine oxide. Both complexes are characterized by single-crystal X-ray diffraction studies. Pseudo-pentagonal bipyramidal geometry (pseudo-D5h) around the lanthanide centers in both complexes is confirmed through SHAPE analysis. Dynamic magnetic measurements revealed the single-ion magnet behavior for both complexes. However, the energy barrier (Ueff) and relaxation time (τ0) for complex 1are extracted as Ueff = 34.77 K, τ0 = 8.07 × 10−7 s (considering both Orbach and Raman processes). These observed phenomena have been corroborated with the aid of CASSCF-based ab initio calculations.