American Chemical Society
cg3c00876_si_001.pdf (1.32 MB)

Structure and Magnetism of LnIII2 (Ln = Gd, Tb, Dy, and Ho) Assemblies Constructed from a Bis(Hydrazone) Compartmental Ligand: Slow Magnetic Relaxation in the DyIII2 Analogue

Download (1.32 MB)
journal contribution
posted on 2023-08-25, 19:06 authored by Priyabrata Bhattacharya, Riya Bag, Soumya Satpathi, Swapan K. Pati, Ray J. Butcher, Jinkui Tang, Sanchita Goswami
The aim of the paper was to synthesize a series of LnIII2 (Ln = Gd, Tb, Dy, and Ho) complexes that offer a great perspective to construct functional magnetic materials. Here, we have ventured a Schiff base ligand by combining 2,6-diformyl-4-methylphenol with 2-hydroxy-benzoic acid hydrazide, and the ligand is reacted with Ln(NO3)3·6H2O (1:1), which affords [Ln2(H2L)3](NO3)3 (Ln = Gd, Dy, and Ho) and [Ln2(H2L)3](NO3)3(CH3OH) (Ln = Tb) complexes. Structural analyses illustrate that the four complexes have a stoichiometry of 2:3 (M:L), wherein three phenolic oxygen atoms are simultaneously coordinated with two metal atoms to form LnIII–Ophenoxo–LnIII bridges. Variable-temperature magnetic susceptibility measurements have been performed in the 2–300 K region for all of the compounds. Magnetic studies indicate that the DyIII2 analogue exhibits the slow relaxation of magnetization behavior under 700 Oe external dc field with an energy barrier of 2.97–7.73 K. The alternating current (ac) magnetic susceptibility measurements were also performed on the 90:10 (Y:Dy) diluted sample analogue and they depicted that the slow magnetic relaxation properties originated mostly from the single ion but not the coupling between DyIII ions. The best-fitting results provided Ueff values of 1.61–2.90 K with τ0 values of 1.31 × 10–5–6.97 × 10–4 s for the diluted sample of DyIII under 500 Oe dc field.