Synthesis, structure, solid-state thermal decomposition and magnetic properties of binuclear Nd, Gd and Eu cymantrenecarboxylates

• Published in: Polyhedron Vol. 30; no. 15; pp. 2523 - 2529
• Main Authors: Koroteev, P.S., Kiskin, M.A., Dobrokhotova, Zh.V., Bogomyakov, A.S., Efimov, N.N., Novotortsev, V.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 21-09-2011
• Subjects: Cymantrenecarboxylate ligands; Heterometallic REE complexes; Magnetic properties; Phase transition; REE manganites; Thermal decomposition; X-ray diffraction study; X-ray diffraction study; Thermal decomposition; Cymantrenecarboxylate ligands; Heterometallic REE complexes; REE manganites; Magnetic properties; Phase transition
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2011.06.035

Three novel 3d–4f heterometallic binuclear carboxylate complexes containing a cymantrene moiety, [Nd
2(μ
2-OOCCym)
4(OOCCym)
2(THF)
4] (
1) and [Ln
2(μ
2-OOCCym)
4(OOCCym)
2(THF)
4]·THF (Ln
=
Gd (
2), Eu (
3); Cym
=
(η
5-C
5H
4)Mn(CO)
3) were synthesized and characterized by X-ray analysis. The magnetic measurements of
2 reveal antiferromagnetic coupling between the Gd atoms at liquid helium temperature. Thermal decomposition of the complexes in air gives rise to a mixture of LnMn
2O
5 and Mn
2O
3.
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► New binuclear lanthanide cymantrenecarboxylate complexes were synthesized. ► Thermal decay of Ln cymantrenecarboxylates under air results in LnMn
2O
5 and Mn
2O
3. ► Antiferromagnetic coupling between the Gd atoms in Gd cymantrenecarboxylate was found.
New rare-earth cymantrenecarboxylates [Nd
2(μ
2-OOCCym)
4(OOCCym)
2(THF)
4] (
1) and [Ln
2(μ
2-OOCCym)
4(OOCCym)
2(THF)
4]·THF (Ln
=
Gd (
2), Eu (
3); Cym
=
(η
5-C
5H
4)Mn(CO)
3) were synthesized starting from carboxycymantrene and lanthanide nitrates, and characterized by X-ray diffraction. The crystals of
1–
3 consist of isolated binuclear molecules; the Ln atoms are eight-coordinate. The magnetic properties of
2 are indicative of antiferromagnetic coupling between the Gd atoms at liquid helium temperature. The thermal decomposition of complexes
1–
3 was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). According to the X-ray powder diffraction patterns, the thermal decomposition of the complexes in air affords a mixture of LnMn
2O
5 and Mn
2O
3 as the final products.