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41.
Bonnet F Visseaux M Barbier-Baudry D Hafid A Vigier E Kubicki MM 《Inorganic chemistry》2004,43(12):3682-3690
The reaction of Ln(BH(4))(3)(THF)(3) or LnCl(3)(THF)(3) with 1 equiv of KCp*' ligand (Cp' = C(5)Me(4)n-Pr) afforded the new monocyclopentadienyl complexes Cp*'LnX(2)(THF)(n) (X = BH(4), Ln = Sm, n = 1, 1a, Ln = Nd, n = 2, 1b; X = Cl, Ln = Sm, n = 1, 3a) and [Cp*'LnX(2)](n') (X = BH(4), n' = 6, Ln = Sm, 2a, Ln = Nd, 2b; X = Cl, Ln = Nd, 4b). All these compounds were characterized by elemental analysis and (1)H NMR. Crystals of mixed borohydrido/chloro-bridged [Cp*'(6)Ln(6)(BH(4))(12-x))Cl(x)(THF)(n')] (x = 10, n' = 4, Ln = Sm, 2a', Ln = Nd, 2b'; x = 5, n = 2, Ln = Sm, 2a' ') were also isolated. Compounds 2a, 2b, 2a', 2b', and 2a' were structurally characterized; they all exhibit a hexameric structure in the solid state containing the [Cp*(3)Ln(3)X(5)(THF)] building block. The easy clustering of THF adducts first isolated is illustrative of the well-known bridging ability of the BH(4) group. Hexameric 2a was found to be unstable in the presence of THF vapors; this may be correlated to the opening of unsymmetrical borohydride bridges observed in the molecular structure. 相似文献
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Isoprene–Styrene Chain Shuttling Copolymerization Mediated by a Lanthanide Half‐Sandwich Complex and a Lanthanidocene: Straightforward Access to a New Type of Thermoplastic Elastomers 下载免费PDF全文
Dr. Andreia Valente Dr. Gregory Stoclet Dr. Fanny Bonnet Prof. André Mortreux Prof. Marc Visseaux Prof. Philippe Zinck 《Angewandte Chemie (International ed. in English)》2014,53(18):4638-4641
A lanthanide half‐sandwich complex and a ansa lanthanidocene have been assessed for isoprene–styrene chain shuttling copolymerization with n‐butylethylmagnesium (BEM). In the presence of 1 equiv BEM, a fully amorphous multiblock microstructure of soft and hard segments is achieved. The microstructure consists of poly(isoprene‐co‐styrene) blocks, with hard blocks rich in styrene and soft blocks rich in isoprene. The composition of the blocks and the resulting glass transition temperatures (Tg) can be easily modified by changing the feed and/or the relative amount of the catalysts, highlighting a new class of thermoplastic elastomers (TPEs) with tunable transition temperatures. The materials self‐organize into nanostructures in the solid state. 相似文献
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Xue-Mei Gao Fanny Shuk Fan Lai Chun-Feng Qiao Xin Liu Kathy Qian Luo Hong-Xi Xu 《Tetrahedron letters》2010,51(18):2442-2446
Four novel polyisoprenylated benzophenone derivatives, paucinones A-D (1-4), were isolated from the leaves of the plant Garcinia paucinervis. Paucinones A-C (1-3) contained an unexpected cyclohexane-spiro-tetrahydrofuran moiety. A 1-methylene-3,3-dimethylcyclohexane group never reported before was found in the structure of paucinone D (4). The structures of these compounds were elucidated with spectroscopic evidences. The relative stereochemistries of 1-4 were determined by NOESY correlations. These compounds showed significant cytotoxicities against HeLa cells. 相似文献
45.
M. Eugenia Sesto Cabral Fanny I. Schabes E. Elizabeth Sigstad 《Thermochimica Acta》2010,497(1-2):14-20
The effect of the CHCl3 and MeOH extracts from aerial parts from the Northwestern Argentina endemic species Ixorhea tschudiana Fenzl. on germination of the dicot tomato and the monoct onion and on soil microbial activity was studied by calorimetric and calorespirometric experiments. The CHCl3 extract inhibited seedling growth of tomato which increased with increasing concentrations. Seeds imbibed with 250 mg dm?3 extract germinated 24 h later than control and those imbibed with 100 and 500 mg dm?3 extract. This was reflected in the calculated low specific seedling growth rate (pSGΔHB) as determined from calorespirometric experiments. On the other hand, seedlings obtained in 500 mg dm?3 extract showed shorter and thicker hairy roots than control with significantly higher pSGΔHB. Probably, the extract induces inhibition of water uptake by seedling roots. Germination was reduced 50% in onion seeds imbibed with 500 mg dm?3 CHCl3 extract which apparently is due to higher rate of imbibition during the first stages as determined for calorimetry. On the other hand, 83 and 250 mg kg?1 of the MeOH and CHCl3 extract seem to selectively inhibit the growth of certain microorganisms and to enhance the activity of soil actinomycetes. Two actinobacteria were isolated from soil treated with these concentrations of both extracts: Kocuria sp. and Kocuria rosea; this latter species is known as a keratinolytic agent and seems to degrade complex carbon compounds of the soil and those incorporated by the MeOH extract. Both Kocuria specie seem to be beneficial for the soil converting substrate into biomass and thus I. tschudiana could be used as a soil phytoremediator. 相似文献
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Anosov representations of word hyperbolic groups into higher-rank semisimple Lie groups are representations with finite kernel and discrete image that have strong analogies with convex cocompact representations into rank-one Lie groups. However, the most naive analogy fails: generically, Anosov representations do not act properly and cocompactly on a convex set in the associated Riemannian symmetric space. We study representations into projective indefinite orthogonal groups \(\mathrm {PO}(p,q)\) by considering their action on the associated pseudo-Riemannian hyperbolic space \(\mathbb {H}^{p,q-1}\) in place of the Riemannian symmetric space. Following work of Barbot and Mérigot in anti-de Sitter geometry, we find an intimate connection between Anosov representations and a natural notion of convex cocompactness in this setting. 相似文献
48.
Phouratsamay Siao-Leu Kedad-Sidhoum Safia Pascual Fanny 《4OR: A Quarterly Journal of Operations Research》2021,19(2):235-264
4OR - We consider the coordination of planning decisions of a single product in a supply chain composed of one supplier and one retailer, by using contracts. We assume that the retailer has the... 相似文献
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Volker Pohl Fanny Yang Holger Boche 《Journal of Fourier Analysis and Applications》2014,20(6):1212-1233
This paper considers the recovery of continuous signals in infinite dimensional spaces from the magnitude of their frequency samples. It proposes a sampling scheme which involves a combination of oversampling and modulations with complex exponentials. Sufficient conditions are given such that almost every signal with compact support can be reconstructed up to a unimodular constant using only its magnitude samples in the frequency domain. Finally it is shown that an average sampling rate of four times the Nyquist rate is enough to reconstruct almost every time-limited signal. 相似文献