Novel heterometallic polymeric lanthanide acetylacetonates with bridging cymantrenecarboxylate groups – synthesis, magnetism and thermolysis. (14th December 2015)

• Record Type: Journal Article
• Authors: Gavrikov, Andrey V.; Koroteev, Pavel S.; Dobrokhotova, Zhanna V.; Ilyukhin, Andrey B.; Efimov, Nikolay N.; Kirdyankin, Denis I.; Bykov, Mikhail A.; Ryumin, Mikhail A.; Novotortsev, Vladimir M.
• Is Part Of: Polyhedron. Volume 102(2015)
• Page Start: 48
• Page End: 59
• Publication Date: 2015-12-14
• Subjects: Cymantrenecarboxylate -- β-Diketonate -- Magnetic properties -- Thermal decomposition -- Lanthanide manganites; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2015.07.063
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Novel coordination polymers, [Ln(acac)2 (OOCCym)(H2 O)] n, were synthesized and investigated. Thermal decomposition of the complexes [Ln(acac)2 (OOCCym)(H2 O)] n in air affords pure LnMnO3 (Ln = Eu, Gd, Tb, Dy) phases. The magnetic properties of all LnMnO3 prepared by thermolysis of the corresponding precursors were studied. Abstract: New isostructural complexes [Ln(CymCOO)(acac)2 (H2 O)] n (Ln = Eu (1 ), Gd (2 ), Tb (3 ), Dy (4 ), Ho (5 ), Er (6 ), acac – acetylacetonate (pentane-2, 4-dionate) anion) having a polymeric structure based on CymCOO-bridged {Ln(acac)2 (H2 O)} fragments were prepared by exchange reactions of hydrated Ln acetylacetonates with CymCOOH (Cym = (η 5 -C5 H4 )Mn(CO)3 ) in a CHCl3 –EtOH–H2 O mixture. For the synthesized complexes comprising diamagnetic cymantrenyl moieties the temperature dependences of the dc magnetic susceptibility were studied in the temperature range of 300–2 K under an applied magnetic field of 5 kOe. Slow magnetic relaxation was found in complexes4 and6 . The thermal decomposition of the complexes was studied by TGA and DSC in the 30–600 °C temperature range in air and under Ar atmosphere. In the former case, the reaction affords LnMnO3 phases. The first step of the thermal decomposition of6 was studied by the kinetic analysis. For the Dy and Ho complexes, standard thermodynamic functions were calculated from adiabatic calorimetry data. Manganites LnMnO3 (Ln = Eu, Gd, Tb, Dy) were synthesized from the corresponding complexes, and their magnetic properties were studied.