Heterometallic Octanuclear Ni^II ₄Ln^III ₄ (Ln = Y, Gd, Tb, Dy, Ho, Er) Complexes Containing Ni^II ₂Ln^III ₂O₄ Distorted Cubane Motifs: Synthesis, Structure, and Magnetic Properties.

ABSTRACT: The reaction of 2-methoxy-6-[{2-(2-hydroxyethylamino)ethylimino}methyl] phenol (LH₃) with lanthanide metal salts followed by the addition of nickel acetate allowed isolation of a family of octanuclear complexes, [Ni₄Ln₄(?₂-OH)₂(?₃-OH)₄(?-OOCCH₃)₈(LH₂)₄]·(OH)₂·xH₂O. Single crystal X-ray diffraction studies of these complexes reveal that their central metallic core consists of two tetranuclear [Ni₂Ln₂O₄] cubane subunits fused together by acetate and hydroxide bridges. The magnetic study of these complexes reveals a ferromagnetic interaction between the Ln^III and the Ni^II center. The magnitude of exchange coupling between the Ni^II and Ln^III center, parametrized from the magnetic data of the Gd analogue, gives J = +0.86 cm^-1. The magneto caloric effect, studied for the Ni^II ₄Gd^III ₄ complex, shows a maximum of magnetic entropy change, -?S _m = 22.58 J kg^-1 K^-1 at 3 K for an applied external field of 5 T.

SUBMITTER: Kalita P 

PROVIDER: S-EPMC6641754 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature