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131.
132.
Self assembly of N-salicylidene 2-aminopyridine (L1H) with Cu(NO3)2·3H2O affords [Cu4(L1)4(NO3)3(CH3OH)][Cu(L1)(NO3)2](2-aminopyridinium)(NO3)·5CH3OH (1) which is composed of an asymmetric [2 × 2] grid-like cationic complex that co-crystallizes with a Cu(II) mononuclear anion. This remarkable tetranuclear unit presents three penta-coordinated and one hexa-coordinated Cu(II) sites. This quadruple helicate structure reveals strong anti-ferromagnetic coupling (J = −340(2) cm−1) between Cu(II) ions through a double alkoxo bridge. Reacting L1H with Cu(NO3)2·3H2O in slightly different conditions affords however a more symmetric tetranuclear grid-like complex: [Cu4(L1)4(NO3)2(OH)2](2-aminopyridinium)(OH)·CH3OH) (2). A dinuclear Ni(II) complex, [Ni2(L2)2(L2H)2(NCS)2(CH3OH)2]·2CH3OH (3), obtained with another related donor ligand (L2H = N-salicylidene 3-aminomethylpyridine) was also prepared. 相似文献
133.
Yann Molard Dr. Frederick Dorson Konstantin A. Brylev Dr. Michael A. Shestopalov Yann Le Gal Stéphane Cordier Dr. Yuri V. Mironov Dr. Noboru Kitamura Prof. Christiane Perrin Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(19):5613-5619
The embedding of functional inorganic entities into polymer matrices has become an intense field of investigation in which the main challenges are to keep the added value of the inorganic entities while preventing their self‐aggregation within the organic matrix. We present a simple way to obtain a homogeneous highly red‐NIR luminescent hybrid copolymer that contains covalently bonded nanometric‐sized {Re6} octahedral clusters. The [Re6Sei8(OH)a6]4? cluster complexes are primarily functionalized in two steps with tert‐butylpyridine (TBP) and methacrylic acid (MAC) to give neutral [Re6Se8(TBP)4(MAC)2] building blocks that are copolymerized with methyl methacrylate (MMA) either in solution or in bulk in the presence of azobisisobutyronitrile as an initiator. Several samples containing 0, 0.025, 0.05, and 0.1 wt % of functionalized {Re6} clusters were prepared. As the {Re6} cluster/MMA ratio is very low, the obtained copolymers keep the entire processability of pure poly(methyl methacrylate) (PMMA), as demonstrated by differential scanning calorimetry and thermogravimetric analysis. Voltammetric and luminescence studies also indicate that the intrinsic properties of the clusters are preserved within the polymer matrix. All the samples show a bright (emission quantum yield=0.07), broad, and structureless emission band, which extends from λ=600 nm to more than λ=950 nm, with the maximum wavelength centered around λem=710 nm either in solution or in the solid state. Moreover, the high stability of the incorporated inorganic phosphors prevents the material from photobleaching, and thus the luminescence properties are kept entirely even after nine months of ageing. 相似文献
134.
Yann Ferrand Dr. Emmanuel Klein Dr. Nicholas P. Barwell Matthew P. Crump Dr. Jesus Jiménez‐Barbero Prof. Cristina Vicent Dr. Geert‐Jan Boons Prof. Sampat Ingale Anthony P. Davis Prof. 《Angewandte Chemie (International ed. in English)》2009,48(10):1698-1698
Carbohydrates are slippery customers in water. Camouflaged by solvent‐mimicking hydroxy groups, they make challenging targets, even for natural receptors. In their Communication on page 1775 ff., A. P. Davis and co‐workers describe a synthetic receptor that is remarkably effective for the important β‐N‐acetylglucosaminyl (β‐GlcNAC) unit. The affinities of the receptor are good and its selectivities are excellent, even by the standards of natural carbohydrate‐binding proteins.
135.
Zürcher S Wäckerlin D Bethuel Y Malisova B Textor M Tosatti S Gademann K 《Journal of the American Chemical Society》2006,128(4):1064-1065
Siderophores are natural iron chelators that have been evolutionarily selected to bind to Fe ions with very high binding constants. We utilize these unique properties to bind to metal oxide surfaces using a fragment of the cyanobacterial siderophore anachelin. The resulting poly(ethylene glycol) conjugate forms stable adlayers on TiO2 as has been shown by variable angle spectroscopic ellipsometry and X-ray photoelectron spectroscopy. Moreover, these coated surfaces are highly protein-resistant against the adsorption of full human serum. 相似文献
136.
Let Θ be a point in R
n
. We are concerned with the approximation to Θ by rational linear subvarieties of dimension d for 0 ≤ d ≤ n−1. To that purpose, we introduce various convex bodies in the Grassmann algebra Λ(R
n+1). It turns out that our convex bodies in degree d are the dth compound, in the sense of Mahler, of convex bodies in degree one. A dual formulation is also given. This approach enables
us both to split and to refine the classical Khintchine transference principle. 相似文献
137.
Tangi Aubert Fabien Grasset Stéphane Mornet Etienne Duguet Olivier Cador Stéphane Cordier Yann Molard Valérie Demange Michel Mortier Hajime Haneda 《Journal of colloid and interface science》2010,341(2):201-208
Water-in-oil (W/O) microemulsion is a well-suitable confined reacting medium for the synthesis of structured functional nanoparticles of controlled size and shape. During the last decade, it allowed the synthesis of multi-functional silica nanoparticles with morphologies as various as core–shell, homogenous dispersion or both together. The morphology and properties of the different intermediates and final materials obtained through this route are discussed in the light of UV–Vis–NIR spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and magnetometer SQUID analysis. 相似文献
138.
Rombouts Y Elass E Biot C Maes E Coddeville B Burguière A Tokarski C Buisine E Trivelli X Kremer L Guérardel Y 《Journal of the American Chemical Society》2010,132(45):16073-16084
Although lipo-oligosaccharides (LOSs) are recognized as major parietal components in many mycobacterial species, their involvement in the host-pathogen interactions have been scarcely documented. In particular, the biological implications arising from the high degree of structural species-specificity of these glycolipids remain largely unknown. Growing recognition of the Mycobacterium marinum-Danio rerio as a specific host-pathogen model devoted to the study of the physiopathology of mycobacterial infections prompted us to elucidate the structure-to-function relationships of the elusive end-product, LOS-IV, of the LOS biosynthetic pathway in M. marinum. Combination of physicochemical and molecular modeling methods established that LOS-IV resulted from the differential transfer on the caryophyllose-containing LOS-III of a family of very unusual N-acylated monosaccharides, naturally present as different diastereoisomers. In agreement with the partial loss of pathogenecity previously reported in a LOS-IV-deficient M. marinum mutant, we demonstrated that this terminal monosaccharide conferred to LOS-IV important biological functions, including macrophage activating properties. 相似文献
139.
Karlsson S Boixel J Pellegrin Y Blart E Becker HC Odobel F Hammarström L 《Journal of the American Chemical Society》2010,132(51):17977-17979
Molecular systems that follow the functional principles of photosynthesis have attracted increasing attention as a method for the direct production of solar fuels. This could give a major carbon-neutral energy contribution to our future society. An outstanding challenge in this research is to couple the light-induced charge separation (which generates a single electron-hole pair) to the multielectron processes of water oxidation and fuel generation. New design considerations are needed to allow for several cycles of photon absorption and charge separation of a single artificial photosystem. Here we demonstrate a molecular system with a regenerative photosensitizer that shows two successive events of light-induced charge separation, leading to high-yield accumulation of redox equivalents on single components without sacrificial agents. 相似文献
140.