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211.
Karmakar S Das O Ghosh S Zangrando E Johann M Rentschler E Weyhermüller T Khanra S Paine TK 《Dalton transactions (Cambridge, England : 2003)》2010,39(45):10920-10927
A new dicompartmental dioxime ligand (H(2)L) with m-xylyl spacer between the donor sites has been synthesised by Schiff-base condensation of α,α'-diamino-m-xylene and diacetyl monooxime. The ligand reacts with copper(ii) salts giving rise to hexanuclear tricationic copper(II) cage complexes [Cu(II)(6)(μ(3)-O···H···O-μ(3))L(3)(H(2)O)(6)]X(3) (X = BF(4), 1a; X = ClO(4), 1b). The complexes have been characterised by different analytical and spectroscopic techniques and confirmed the hexanuclear structure even in solution. Single crystal X-ray diffraction studies of both the complexes revealed a very similar core structure with three dicompartmental ligands supporting two triangular Cu(3)O cores that share a proton, located on their common threefold axis and involved in a strong hydrogen bond interaction (O···O distance of 2.517(2) ?). Two Cu(3)O units do not superimpose but are staggered and disposed with the formation of a helicate structure. However both the enantiomers are present in the centrosymmetric space group. The facing Cu(3)-planes in 1a are separated at a distance of 3.476 ?. The temperature dependence of the magnetic behaviour of the hexanuclear complex 1a clearly indicates an overall antiferromagnetic exchange interaction between the spin carriers in the cage having two Cu(3)O subunits and leaves a single unpaired electron in each triangular unit. The unpaired electrons in the two Cu(3)O units interact antiferromagnetically through hydrogen bonding giving rise to an overall singlet-spin ground state. 相似文献
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Alegret N Chaur MN Santos E Rodríguez-Fortea A Echegoyen L Poblet JM 《The Journal of organic chemistry》2010,75(23):8299-8302
The Bingel-Hirsch reactions on non-isolated pentagon rule (non-IPR) Gd(3)N@C(2n) (2n = 82, 84) are studied. Computational results show that the two metallofullerenes display similar reactivity according to their related topologies. Long C-C bonds with large pyramidalization angles lead to the most stable adducts, the [5,6] bonds in the adjacent pentagon pair being especially favored. The lesser regioselectivity observed for Gd(3)N@C(82) is probably due to the activation of some C-C bonds by means of the metal cluster. 相似文献
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We estimate the rate of convergence of products of projections on K finite dimensional or finite codimensional subspaces in ℓ
2 by the rate of convergence of the decreasing sequence of the squares of the norms of the iterates. 相似文献
218.
Eva‐Maria Hein Bertram Bödeker Jürgen Nolte Heiko Hayen 《Rapid communications in mass spectrometry : RCM》2010,24(14):2083-2092
Electrospray ionization mass spectrometry (ESI‐MS) has emerged as an indispensable tool in the field of lipidomics. Despite the growing interest in lipid analysis, there are only a few software tools available for data evaluation, as compared for example to proteomics applications. This makes comprehensive lipid analysis a complex challenge. Thus, a computational tool for harnessing the raw data from liquid chromatography/mass spectrometry (LC/MS) experiments was developed in this study and is available from the authors on request. The Profiler‐Merger‐Viewer tool is a software package for automatic processing of raw‐data from data‐dependent experiments, measured by high‐performance liquid chromatography hyphenated to electrospray ionization hybrid linear ion trap Fourier transform mass spectrometry (FTICR‐MS and Orbitrap) in single and multi‐stage mode. The software contains three parts: processing of the raw data by Profiler for lipid identification, summarizing of replicate measurements by Merger and visualization of all relevant data (chromatograms as well as mass spectra) for validation of the results by Viewer. The tool is easily accessible, since it is implemented in Java and uses Microsoft Excel (XLS) as output format. The motivation was to develop a tool which supports and accelerates the manual data evaluation (identification and relative quantification) significantly but does not make a complete data analysis within a black‐box system. The software's mode of operation, usage and options will be demonstrated on the basis of a lipid extract of baker's yeast (S. cerevisiae). In this study, we focused on three important representatives of lipids: glycerophospholipids, lyso‐glycerophospholipids and free fatty acids. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Eva Sjöblom Thomas Edberg Per Stenius 《Journal of Dispersion Science and Technology》2013,34(2):123-145
The phase diagrams for the system TRS 10-80/ butanol/Petrol D/sodium chloride show that the weight ratio B = TRS/butanol is very important for the stability of the microemulsion. R = 1 results in a very limited microemulsion region. Provided the ratio is >1.22 the minimum amount of (TRS+butanol) necessary to form a microemulsion, with equal amounts of water and Petrol D, is 15% and approximately independent of R.However, as R is increased the solubility of water in the (TRS+butanol) mixture is reduced and a liquid crystalline phase is formed. Its presence increases the viscosity and the kinetic stability of the emulsions formed at low content of Petrol D. Addition of electrolyte reduces the minimum amount of (TRS+butanol) necessary to form a microemulsion. Furthermore, systems rich in water separate into two phases; an upper microemulsion phase and a lower aqueous phase. This can be explained in terms of a redistribution of the butanol from the aqueous phase to the oil phase. It is shown that, although the studied system contains unpurified technical products, the phase behaviour is very similar to that of model systems of pure chemicals. X-ray diffraction showed that the liquid crystal line phase was lamellar. The thickness of the amphiphilie layer was 26-28 Å. It is more difficult to obtain direct information of the structure of the microemulsion. However, conductivity data indicated a “bicontinuous” structure or at least, the occurrence of highly dynamic aggregates over a large concentration range. 相似文献