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Carsten Thöne Jörg Laube Stefan Jäger 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):641-644
Organometallic tungsten selenido complexes of the type [cpW(CO)3]2Sem; m = 2 (1), 3 (2), 4 (3), can be easily synthesized via insertion of selenium into the alkali-metal tungsten bond of LiWcp(CO)3 in appropriate ratios and subsequent oxidation of the produced W-selenolates with O2/SiO2. In contrast, reactions of K2Se6 with [cpW(CO)3Cl] and 18-crown-6 in DMF lead to a mixture óf [cpW(CO)3]2Se4 (3), the η1 Se-bonded selenocarbamato complex [cpW(CO)3SeC(O)NMe2] (4) and the ionic complex [(18-crown-6)K]+[cpW(Se4)2]? (5). The crystal structures of 3 and 4 together with their 77Se NMR data are presented. 相似文献
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Katrin Loeschner Jana Navratilova Carsten Købler Kristian Mølhave Stephan Wagner Frank von der Kammer Erik H. Larsen 《Analytical and bioanalytical chemistry》2013,405(25):8185-8195
A method of analysis of silver nanoparticles (AgNPs) in chicken meat was developed. The homogenized chicken meat sample, which was spiked with AgNPs, was subjected to enzymolysis by Proteinase K for 40 min at 37 °C. Transmission electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS) in single particle mode were used to characterize the number-based size distribution of AgNPs in the meat digestate. Because similar size distributions were found in the meat digestate and in the aqueous suspension of AgNPs used for spiking the meat, it was shown that no detectable dissolution of the AgNPs took place during the sample preparation stage. The digestate was injected into the asymmetric flow field flow fractionation (AF4) -ICP-MS system, which enabled fractionation of nanoparticles from the remaining meat matrix, and resulted in one large peak in the fractograms as well as two smaller peaks eluting close to the void volume. The recovery of silver contained in the large AgNP peak was around 80 %. Size determination of AgNPs in the meat matrix, based on external size calibration of the AF4 channel, was hampered by non-ideal (early elution) behavior of the AgNPs. Single particle ICP-MS was applied for determination of the number-based particle size distribution of AgNPs in collected fractions. The presented work describes for the first time the coupling of AF4 and ICP-MS for AgNP separation in a food matrix. 相似文献
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Md Lutfor Rahman Jahimin Asik Sandeep Kumar Carsten Tschierske 《Liquid crystals》2013,40(11):1263-1270
Three banana‐shaped monomers, i.e. 2,7‐naphthalene bis[4‐(4‐allyloxyphenylazo)‐benzoate], 2,7‐naphthalene bis[4‐(4‐allyloxy‐3‐fluorophenylazo)benzoate] and 2,7‐naphthalene bis{4‐[4‐(10‐undecenyloxy)phenylazo]benzoate}, containing azobenzene as side arms, 2,7‐dihydroxynaphthalene as central units and terminal double bonds as polymerisable functional groups, were synthesised and their mesophase behaviour investigated. Polarizing optical microscopy and DSC measurements reveal that all compounds exhibit nematic mesophases. The absorption spectrum of the trans‐azobenzene groups displays a high‐intensity π–π* transition at about 365 nm and a low‐intensity n–π* transition at around 450 nm for all compounds. Hence, photochromism can be achieved by the introduction of the azo linkage to banana‐shaped liquid crystals molecules. 相似文献