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991.
Caterina Viglianisi Stefano Menichetti Giulio Assanelli Maria Carmela Sacchi Incoronata Tritto Simona Losio 《Journal of polymer science. Part A, Polymer chemistry》2012,50(22):4647-4655
A new family of ethylene‐based copolymers with controlled amounts of a norbornene comonomer (NArOH) bearing a stabilizing antioxidant functionality (2,6‐di‐tert‐butyl phenol) was prepared. Due to unavoidable exo/endo equilibrium operative in NArOH comonomer, a complete and detailed NMR assignment of the structure of the prepared ethylene/NArOH copolymers was carried out for the determination of the exo/endo ratio inside the polymer. These novel functionalized comonomers can be considered suitable starting material for preparing ethylene‐based copolymers, with tunable comonomer content, as non‐releasing macromolecular antioxidant additives for specific application in safe food and/or drug packaging © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Yanpeng Xue Eirini Maria Paschalidou Paola Rizzi Livio Battezzati Hans-Jörg Fecht 《哲学杂志》2018,98(30):2769-2781
Nanoporous gold thin films have been fabricated through chemical de-alloying of Au-based nanoglass with a nanocolumnar structure, with composition Au40Cu28Ag7Pd5Si20 (at.%), that had previously been deposited by magnetron sputtering. By varying the de-alloying conditions, gold ligaments ranging from 20 to 100?nm were obtained. The microstructure and chemical composition of the as-prepared films were characterised by various techniques. Surface-enhanced Raman scattering (SERS) of thin films was investigated using rhodamine 6G. The results indicate that the main microstructural features with interconnected ligaments and defects of nanoporous gold result in significant SERS enhancement. 相似文献
995.
New insights into water‐soluble and water‐coordinated copper 15‐metallacrown‐5 gadolinium complexes designed for high‐field magnetic resonance imaging applications 下载免费PDF全文
Marina A. Katkova Galina S. Zabrodina Evgeny V. Baranov Maria S. Muravyeva Evgeny A. Kluev Andrey S. Shavyrin Grigory Yu Zhigulin Sergey Yu Ketkov 《应用有机金属化学》2018,32(7)
The development of contrast agents specifically designed for high‐field magnetic resonance imaging (MRI) is required because the relaxation efficiency of classic Gd(III) contrast agents significantly decreases with increasing magnetic field strengths. With an idea of exploring the unique structure of lanthanide (Ln) 15‐MC‐5 metallacrowns, we developed a series of water‐soluble Gd(III) aqua‐complexes, bearing aminohydroxamate (glycine, α‐alanine, α‐phenylalanine and α‐tyrosine) ligands, with increasing number of water molecules directly coordinated to the Gd(III) ion: Gd(H2O)4[15‐MCCu(II)Glyha‐5](Cl)3 ( 1 (Gd)), Gd(H2O)4[15‐MCCu(II)Alaha‐5](Cl)3 ( 2 (Gd)), Gd(H2O)3[15‐MCCu(II)Phalaha‐5](Cl)3 ( 3 (Gd)) and Gd(H2O)3[15‐MCCu(II)Tyrha‐5](Cl)3 ( 4 (Gd)). In these systems, the Ln(III) central ion is coordinated by five oxygen donor atoms of the ligands and three or four inner‐sphere water molecules. The X‐ray crystal structure of metallacrown Ln(H2O)3,4[15‐MCCu(II)Rha‐5]3+ agrees with density functional theory predictions. The calculations demonstrate that the exchange of coordinated water molecules can proceed easily, resulting in increased relaxivity parameters. The longitudinal relaxivities (r1) of 1 (Gd)– 4 (Gd) in water at ultrahigh magnetic field of 9.4 T were determined to be 11.5, 14.8, 13.9 and 12.2 mM?1 s?1, respectively. The ability to increase the number of Ln(III) inner‐sphere water molecules up to four, the planar metallacrown structure and the rich hydration shell due to strong hydrogen bonds between the [15‐MC‐5] moiety and bulk water molecules provide new opportunities for potential MRI applications. 相似文献
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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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