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991.
Cristiana Cesari Iacopo Ciabatti Cristina Femoni Maria Carmela Iapalucci Stefano Zacchini 《Journal of Cluster Science》2017,28(4):1963-1979
The reactions of [Ni16(C2)2(CO)23]4? and [Ni38C6(CO)42]6? with CuCl afforded mixtures of the previously reported [HNi42C8(CO)44(CuCl)]7? bimetallic octa-carbide cluster and the new [HNi43C8(CO)45]7? and [HNi44C8(CO)46]7? homo-metallic octa-carbides. The three species have very similar properties resulting always in co-crystals such as [NMe4]7[HNi42+2xC8(CO)44+2x(CuCl)1?x]·6.5MeCN (x = 0.14) (86% [HNi42C8(CO)44(CuCl)]7?, 14%[HNi43C8(CO)45]7?/[HNi44C8(CO)46]7?) and [NMe4]7[HNi42+2xC8(CO)44+2x(CuCl)1?x]·5.5MeCN (x = 0.30) (70% [HNi42C8(CO)44(CuCl)]7?, 30% [HNi43C8(CO)45]7?/[HNi44C8(CO)46]7?). The new homo-metallic octa-carbides can be obtained free from the Ni–Cu octa-carbido cluster by reacting [Ni10(C2)(CO)16]2? in thf with a stoichiometric amount of CuCl, and crystals of [NMe4]6[H2Ni43+xC8(CO)45+x]·6MeCN (x = 0.72), which contain [H2Ni44C8(CO)46]6? (72%) and [H2Ni43C8(CO)45]6? (28%), have been obtained. Despite the different charges and compositions, these anions display almost identical structures, which are also closely related to those previously reported for the bimetallic Ni–Cd octa-carbido clusters [Ni42+xC8(CO)44+x(CdCl)]7? and [HNi42+xC8(CO)44+x(CdBr)]6?. Indeed, all these clusters are based on the same Ni42C8 cage decorated by miscellaneous [CdX]+ (X = Cl, Br), [CuCl] and [Ni(CO)] fragments. 相似文献
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A polyacrylonitrile (PAN) homopolymer and a copolymer with methyl acrylate were analyzed by differential scanning calorimetry (DSC) in order to establish a method for the kinetic analysis of the stabilization reaction steps during heat treatment. The application of a program rarely used for the study of the chemical transformation of PAN and its copolymers resulted in five separate steps, which can be assigned with large probability to various cyclization and oxidation reactions. A more exact identification of the reactions needs further measurements and considerations. Overlapping peaks appearing in the DSC traces were deconvoluted and then quantitatively analyzed to obtain kinetic parameters. The kinetics of the processes were described by the Kissinger model. The model could be fitted well to four of the five processes that may indicate that these belong to individual reactions of the first order. The parameters obtained agree well with the few values of similar investigations published in the literature up to now. The results have large practical relevance, since the kinetic parameters obtained can be used in the preparation of intermediates and for the optimization of the stabilization process. 相似文献
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Diffuse double layers merge in narrow electrochemical cells. The distribution of ions, and the accompanying electrical properties, are predicted under static conditions that are mild enough not to engender electrochemical reactions. The predictions rest on assumptions that are not egregiously unreasonable. The potential and concentration profiles are respectively described by Legendre elliptic integrals and Jacobian elliptic functions. The special case of pure water is examined and the relevance of this study to water desalination is briefly addressed. 相似文献
1000.