The Use of Malonate Coordination Polymers with Cu super(II) and Ba super(II) Atoms for Barium Cuprate Preparation

• Published in: European journal of inorganic chemistry 2015-07, Vol.2015 (19), p.3116-3127
• Main Authors: Dobrokhotova, Zhanna V, Gogoleva, Natalya V, Zorina-Tikhonova, Ekaterina N, Kiskin, Mikhail A, Chernyshev, Vladimir V, Emelina, Anna L, Bukov, Mikhail A, Goloveshkin, Alexander S, Bushmarinov, Ivan S, Sidorov, Aleksey A, Bogomyakov, Artem S, Kovba, Maksim L, Novotortsev, Vladimir M, Eremenko, Igor L
• Format: Article
• Language: English
• Subjects: ATOMS; Coordination polymers; COPPER OXIDE; COPPER SULFATE; CRYSTAL STRUCTURE; Crystals; DECOMPOSITION; Dehydration; Dicarboxylic acids; Formations; POLYMERS; Thermal decomposition; THERMOGRAVIMETRIC ANALYSIS; Three dimensional
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201500243

The reactions of CuSO sub(4).5H sub(2)O and Ba(R sub(2)mal) [R sub(2)mal super(2-) is the dianion of 1,1-cyclopropanedicarboxylic acid (H sub(2)Cpdc), 1,1-cyclobutanedicarboxylic acid (H sub(2)Cbdc), or butylmalonic (H sub(2)Bumal) acid] in water give crystals of the 3D coordination polymers [BaCu(Cpdc) sub(2)] sub(n)(1), [BaCu(Cbdc) sub(2)(H sub(2)O)] sub(n)(2) and [Ba sub(3)Cu sub(3)(Bumal) sub(6)(H sub(2)O) sub(11)] sub(n)2n(H sub(2)O ) (3). The heating of 2 in air to 200 degree C for 60 min results in the removal of the coordinated water molecules to give anhydrous [BaCu(Cbdc) sub(2)] sub(n)(4). The structures of 1-3 were determined by single-crystal XRD, and that of 4 was derived from powder XRD (XPRD) data. It was assumed that the crystal structures of the polymer complexes that we isolated were determined, to a considerable extent, by the nature of the substituent of the dicarboxylic acid. For 2, the dicarboxylic acid contains closed cyclic moieties, which are retained during dehydration to give 4. A comparative study of the thermal decomposition processes and thermal kinetics of 1-3 showed that the dehydration proceeds by a single scheme, and the bonds between the structural moieties in the anhydrous intermediates become stronger. The thermal destruction of the anhydrous compounds 1, 4 and {3} [the dehydrated intermediate of the thermal decomposition of 3, as proved by thermogravimetric analysis (TGA) data] occurs above 170 degree C. The phase compositions of their solid products are determined by the thermolysis conditions, and the formation of BaCuO sub(2) from 3 can be realized under milder conditions than those for the formation from 1 and 2. Combinations of CuSO sub(4) and barium salts of substituted malonic acids produce 3D coordination polymers with various new topologies. The solid-phase thermolysis of the anhydrous polymers under specially selected conditions results in the target BaCuO sub(2) crystalline phase.