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Jens Langer Sven Krieck Reinald Fischer Helmar Görls Matthias Westerhausen Prof. Dr. 《无机化学与普通化学杂志》2010,636(7):1190-1198
Iodide is a very soft and large anion and as such its extreme ability to be polarized leads to a flat energy surface with respect to the variation of the Ca–I distances in [(L)nCaI2] and [(L)nCa(R)I]. The influence of the donor strength and the bulkiness of the neutral coligands L on the Ca–I distances is studied. The base adducts of calcium diiodide can be isolated after the addition of L to CaI2 or from the Schlenk equilibrium after the direct synthesis of calcium powder with aryl iodides. As L the ethers diethyl ether (Et2O), tetrahydrofuran (thf), tetrahydropyran (thp), 1,2‐dimethoxyethane (dme), 18‐crown‐6 (18C6), bis(methoxyethyl)ether (diglyme), and amines tetramethylethylenediamine (tmeda), and hexamethyltriethylenetetramine (hmteta) are studied yielding the adducts [(thp)4Ca(Ph)I] ( 1a ), [(thf)4Ca(Ph)I] ( 1b ), [(dme)2(thf)Ca(Ph)I] ( 1c ), [(18C6)Ca(Ph)I] ( 1d ), and [(tmeda)2Ca(Ph)I] ( 1e ), as well as [(thp)4CaI2] ( 2a ), [(thf)4CaI2] ( 2b ), [(Et2O)4CaI2] ( 2c ), [(diglyme)(thf)2CaI2] ( 2d ), [(diglyme)(dme)CaI2] ( 2e ), [(dme)2(thf)CaI2] ( 2f ), [(18C6)CaI2] ( 2g ), [(tmeda)2CaI2] ( 2h ), and [(hmteta)CaI2] ( 2i ). For comparison reasons, [(thf)4Ca(Ph)Br] ( 3a ), [(thp)4CaBr2] ( 4a ), [(thf)4CaBr2] ( 4b ), and [(dme)2(AcOH)CaBr2] ( 4c ) with AcOH being acetic acid are included as well. The comparison shows that the coordination number of calcium itself only plays an insignificant role whereas bulkiness and donor strength of L represent the key influences. 相似文献
84.
Aurélie Fischer 《Journal of multivariate analysis》2010,101(9):2207-2221
This paper deals with the problem of quantization of a random variable X taking values in a separable and reflexive Banach space, and with the related question of clustering independent random observations distributed as X. To this end, we use a quantization scheme with a class of distortion measures called Bregman divergences, and provide conditions ensuring the existence of an optimal quantizer and an empirically optimal quantizer. Rates of convergence are also discussed. 相似文献
85.
Asad Ali Munawar Hussain Imran Malik Alexander Villinger Christine Fischer Peter Langer 《Helvetica chimica acta》2010,93(9):1764-1772
Double Heck cross‐coupling reactions of 2,3‐ and 3,5‐dibromopyridine with various alkenes afforded the corresponding novel di(alkenyl)pyridines. The Heck reaction of 2,5‐dibromopyridine unexpectedly afforded 5,5′‐di(alkenyl)‐2,2′‐bipyridines by palladium‐catalyzed dimerization to give 5,5′‐dibromo‐2,2′‐bipyridine and subsequent twofold Heck reaction. 相似文献
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Characterization and functionalization of cellulose microbeads for extracorporeal blood purification
Marion Ettenauer Fritz Loth Katrin Thümmler Steffen Fischer Viktoria Weber Dieter Falkenhagen 《Cellulose (London, England)》2011,18(5):1257-1263
In the frame of this work, cellulose microbeads with an average particle size of 2.3 μm were characterized with respect to
porosity using a batch solute exclusion method and two groups of model substances, namely proteins and polystyrene sulfonates.
The pores of the microbeads were almost completely accessible to proteins with Stokes radii below 2.5 nm. More than 60% of
the pores were accessible to albumin, which is relevant for the application in blood purification, since many target substances
are albumin bound. Activation of the microbeads with increasing amounts of sodium metaperiodate yielded matrices with dialdehyde
contents between 100 and 1,000 μmol/g. The activated beads were well suited for the covalent attachment of functional ligands,
such as antibodies. Immobilization of antibodies against the pro-inflammatory cytokine TNF-α resulted in efficient TNF-α adsorbents
which possess application potential in extracorporeal blood purification, e.g. for the modulation of cytokine levels as supportive
therapy for sepsis and other inflammatory disorders. 相似文献
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Dr. Matthias C. Witschel Dr. H. Wolfgang Höffken Michael Seet Dr. Liliana Parra Thomas Mietzner Frank Thater Dr. Ricarda Niggeweg Dr. Franz Röhl Dr. Boris Illarionov Dr. Felix Rohdich Dr. Johannes Kaiser Prof. Dr. Markus Fischer Prof. Dr. Adelbert Bacher Prof. Dr. François Diederich 《Angewandte Chemie (International ed. in English)》2011,50(34):7931-7935