- Bimetallic Salen-Based Compounds and Their Potential Applications
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The new bimetallic coordination compounds [LNiAg(NO3)], [LCuMn(NO3)2], [LCuCu(NO3)2], [LCuZn(NO3)2], and [{LCuBi(NO3)3}(ACN)] have been synthesized from a salen-type ligand L containing two distinct coordination sites to accommodate (different) metal ions M1 and M2. In the solid state, the formation of 1:1 compounds (LCu:M2) is always observed, but interactions between the compounds lead to differences in packing. For example, a head-to-tail arrangement along the crystallographic b-axis is observed in the case of the LCuBi compound, and the LNiAg compound is polymeric, while its Cu homologue LCuAg forms a discrete dimer. Given the inherent potential of the preorganizing, two metal ions using L could be used to synthesize nanoscale copper-bismuth and-manganese mixed metal oxides as a function of the temperature. The combination of different bioactive metal ions within one ligand system was furthermore explored for antimicrobial efficiency.
- Abram, Sarah-Luise,Crochet, Aurélien,Finelli, Alba,Fromm, Katharina M.,Hérault, Nelly
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p. 4945 - 4958
(2020/09/04)
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- Degradation of the Bi,Pb-2223 HTSCs in Contact with Aerial Moisture and Water
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The degradation of HTSC ceramics and powders of compositions Bi1.65Pb0.35Sr1.8Ca2.2Cu 3Ox and Bi1.65Pb0.35Sr1.9Ca2.1Cu 3Ox stored in air of 32-98% humidity and in contact with water is studied. The superconducting phase degrades only insignificantly at room temperature while the air humidity is less than 91%, but degrades at 98% air humidity, in contact with water, or when exposed to elevated temperature. The reactions of the HTSC powders with water at 20 to 60°C are kinetic-controlled; they obey a linear law with an activation energy of 90 kJ/mol.
- Lomonosov,Kononyuk,Makarenko
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p. 1619 - 1622
(2008/10/08)
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- Qualitative study on the reaction of Bi1.8Pb0.4Ca2Sr2Cu3Oy superconductor with water
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When Bi1.8Pb0.4Ca2Sr2Cu3Oy powders were immersed into deionized water, a large quantity of Ca2+ and Sr2+ ions was detected in the aqueous solution, indicating the decomposition of the Bi1.8Pb0.4Ca2Sr2Cu3Oy superconductors in water. The pH of the solution was initially increased rapidly to 11.1 due to the formation of OH- ions. However, after 30 min, in the open system, the Ca2+ and Sr2+ ions would further react with CO2 in the atmosphere to form sparingly soluble carbonates and the pH of the solution was slowly decreased to 9.81 over 20 h. Only a small amount of Bi3+, Pb2+ and Cu2+ ions was detected in the aqueous solution. Non-soluble products, such as Bi2CuO4, CuO and Cu6PbO8, were observed in the reaction residue which might act as a barrier to prevent deterioration of the superconductor with water in the bulk sample. The chemical equation was given as Bi1.8PbxCa2Sr2Cu3Oy(s) + 4H2O → 2Ca(aq)2+ + 2Sr(aq)2+ + 8OH(aq)- + 0.9Bi2CuO4(s) + xCu6PbO8(s) + (3-0.9-6x)CuO(s).
- Wei,Wang,Kao
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p. 179 - 181
(2008/10/08)
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- Kinetic study of Bi1.8Pb0.4Ca2Sr2Cu3Oy superconductor in water
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The reaction of Bi1.8Pb0.4Ca2Sr2Cu3Oy powder in water was studied quantitatively. It was found that the [H3O+] ion would act as a catalyst in this reaction and the initial rate equation was R0 = -d[A]0/dt = k[A]0[H3O+]00.2, where [A] represented the surface area of the superconducting powder. The rate constant, k, obtained at 10, 25 and 40 °C was 3.98, 8.8 and 19.6×10-4 mol min-1 cm-2 M0.8, respectively. The activation energy and pre-exponential factor calculated from the Arrhenius equation were respectively 39.1 kJ mol-1 and 6.4×103 mol min-1 cm-2 M0.8.
- Wang,Wei,Kao
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p. 391 - 394
(2008/10/08)
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