Experimental Evidence of a Ferromagnetic Ground State (S = ⁹/₂) for a Dinuclear Gd(III)−Ni(II) Complex

Abstract

The structural determination of a dinuclear Gd(III)−Ni(II) entity confirms the strict dinuclearity of the complex while the magnetic properties evidence the presence of a ferromagnetic interaction between the paramagnetic (S = 1) nickel ion and the gadolinium center (S = 7/2), with a J value of 3.6 cm-1.

Di‐ or Trinuclear 3d–4f Schiff Base Complexes: The Role of Anions

“…Sodium dicyanamide can also react with 4 to yield L 3 NiNa(N 3 C 2 ) (5). Use of lanthanide triflate in a 1:1 ratio yielded a practically colorless solution, which, upon addition of dichloromethane, produced an off-white precipitate of L 3 NiGd(trif) 3 (H 2 O) 2 (9). Unfortunately, we were not able to isolate crystals corresponding to the 2:1 Ni/Gd ratio by using either gadolinium nitrate (complex 7) or gadolinium triflate.…”

“…Reaction of [L 3 Ni]·1.75H 2 O (4) with lanthanide nitrate salts in a 1:1 ratio in acetone yielded the expected complex [L 3 NiGd(NO 3 ) 3 (H 2 O) 2 ] (6) [9] as a light-purple powder, whereas the same reaction in a 2:1 Ni/Ln ratio produced a beige precipitate formulated as (L 3 Ni) 2 Gd(NO 3 ) 3 (H 2 O) 2 (7). The latter compound can also be obtained from the reaction of 6 with 4 in a 1:1 ratio in acetone.…”

“…[4][5][6][7] Moreover, as such Schiff base ligands are able to chelate several different 3d ions, other couples are accessible. [8] Because these dinuclear entities are well isolated from each other, they are good candidates for studying the unique magnetic interaction that can be active in such complexes, and ferromagnetic interactions have been evidenced in a large majority of heterodinuclear Ni IIGd, [9] Co II -Gd, [10] Fe II -Gd, [11] and VO-Gd [12] complexes. Few literature reports indicate that di-or trinuclear 3d-4f complexes may be isolated by using a 3d complex as a ligand.…”

Structural and Magnetic Study of a Trinuclear MnII–GdIII–MnII Complex

“…Moreover, an isotropic Hamiltonian may be used when gadolinium, with its half-filled 4f orbitals and its 8 S 7/2 ground state, is associated to copper [1][2][3] or vanadyl ions. [4] Although analysis of the Ni-Gd, [5] Co-Gd [6] and Fe-Gd [7] complexes is complicated by the orbital contribution of the 3d ions, these heterodinuclear complexes do exist and also allow such studies. However, an equivalent Mn II -Gd-Schiff base complex has never been synthesized.…”

“…However, an equivalent Mn II -Gd-Schiff base complex has never been synthesized. Our first attempt in this direction yielded an ionic species with two [Mn III -Schiff base] complex cations surrounding a dianionic [Gd(NO 3 ) 5 (MeOH)] entity without any direct bonding interaction between the Mn and Gd centres. [8] Since then, other ligands have been used to fill this gap.…”