Abstract
Novel mononuclear cymantrenecarboxylate complexes of transition metals, [Co(H2O)6](CymCO2)2·4H2O (Cym = (η5-C5H4)Mn(CO)3) (1), [Ni(H2O)6](CymCO2)2·4H2O (2), [Zn(H2O)6](CymCO2)2·4H2O (3), [Co(CymCO2)2(imz)2] (imz = imidazole, 4), [Co(CymCO2)2(bpy)2]·2PhMe (bpy = 2,2′-bipyridyl, 5), [Ni(CymCO2)(bpy)2(H2O)][CymCO2]·0.5MePh·2H2O (6), [Cu(CymCO2)2(imz)2] (7), and [Cu(CymCO2)2(bpy)(H2O)] (8), were obtained and characterized by single-crystal X-ray analysis. Complexes 1–3 are isostructural. Magnetism of the Co complexes 1, 4, and 5 was studied; it was shown that they exhibit the properties of field-induced single-molecule magnets with magnetization reversal barriers (ΔE/kB) of 44, 13, and 10 K, respectively. Thermal decomposition of complexes 1–8 was studied by means of DSC and TGA methods. The final products of thermolysis of 1–6 in air, according to powder XRD data, are the pure spinel phases MMn2O4; for the cases of copper complexes, the mixtures of CuMn2O4 and CuO were found in the products.
Highlights
The formation of polynuclear heterometallic complexes of transition metals in solution was determined by means of physicochemical methods in the 1960s [1]
We have shown that thermolysis of lanthanide cymantrenecarboxylate complexes brings about multiferroic rare-earth manganites LnMnO3 or LnMn2O5 as the solid products, and the type of the manganite formed is determined by the ratio of metals in the initial complex [21,28,45]
The weight loss is completed at 575 °C, which is significantly higher than for the cases of the other cobalt cymantrenecarboxylate complexes under consideration, and the thermal effects are observed over the conditions of the differential scanning calorimetry (DSC) experiment begins above 292 ◦C; it is accompanied by a complex exotherm
Summary
The formation of polynuclear heterometallic complexes of transition metals in solution was determined by means of physicochemical methods in the 1960s [1]. Since the beginning of the 1980s, many various 3d-3d -heterometallic complexes in which different metal ions were bound by typical polydentate ligands (Schiff bases, amino alcohols, amino phenols, amino acids), including carboxylates, were obtained and structurally characterized [3,4,5,6] Interest in such compounds was raised by their potential unusual properties caused by the presence of metal atoms of various nature in one molecule; this made it possible to assume the appearance of fundamentally new properties in these complexes, for example, the magnetic or catalytic ones, due to interaction of the metal ions with each other or due to their synergistic effect. This paper describes the synthesis and the properties of new mononuclear cymantrenecarboxylate complexes of several 3d-transition metals having +2 oxidation state
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
