Dye-doped silica nanoparticles as efficient labels for glycans

We report that dye-doped fluorescent silica nanoparticles (FSNPs) are highly efficient labels for glycans. Mono- and oligo-saccharides were conjugated to FSNPs using a general photocoupling chemistry. FSNP-labeled glycans were applied to image and detect bacteria, and to study carbohydrate-lectin interactions on a lectin microarray.     

Polymere,bandförmige Tellurkationen in den Strukturen des Chloroberyllats Te7[Be2Cl6] und des Chlorobismutats (Te4)(Te10)[Bi4Cl16]

Polymeric, Band Shaped Tellurium Cations in the Structures of the Chloroberyllate Te₇[Be₂Cl₆] and the Chlorobismutate (Te₄)(Te₁₀)[Bi₄Cl₁₆] Te₇[Be₂Cl₆] is obtained at 250 °C in an eutectic Na₂[BeCl₄] / BeCl₂ melt from Te, TeCl₄ und BeCl₂ in form of black crystals, which are sensitive towards hydrolysis in moist air. (Te₄) (Te₁₀)[Bi₄Cl₁₆] is prepared from Te, TeCl₄ und BiCl₃ by chemical vapour transport in sealed evacuated glass ampoules in a temperature gradient 150 ° → 90 °Cin form of needle shaped crystals with a silver lustre. The structures of both compounds were determined based on single crystal X‐ray diffraction data (Te₇[Be₂Cl₆]: orthorhombic, Pnnm, Z = 2, a = 541.60(3), b = 974.79(6), c = 1664.4(1) pm; (Te₄)(Te₁₀)[Bi₄Cl₁₆]: triclinic, P1¯, Z = 2, a = 547.2(3), b = 1321.1(7), c = 1490(1) pm, α = 102.09(5)°, β = 95.05(5)°, γ = 96.69(4)°). The structure of Te₇[Be₂Cl₆] consists of one‐dimensional polymeric cations (Te₇²⁺)_n which form folded bands and of discrete [Be₂Cl₆]^2— anions which form double tetrahedraconnected by a common edge. By a different way of folding compared with the cations present in the structures of Te₇[MOX₄]X (M = Nb, W; X = Cl, Br) the (Te₇²⁺)_n cation in Te₇[Be₂Cl₆]represents a new, isomeric form. The structure of (Te₄)(Te₁₀)[Bi₄Cl₁₆] contains two different polymeric cations. (Te₁₀²⁺)_n consists of planar Te₁₀ groups in the form of three corner‐sharing Te₄ rings connected to folded bands. (Te₄²⁺)_n forms in contrast to the so far notoriously observed discrete, square‐planar E₄²⁺ ions a chain of rectangular planar Te₄ rings (Te—Te 274 and 281 pm) connected by Te‐Te bonds of 297 pm. [Bi₄Cl₁₆]^4— has a complex one‐dimensional structure of edge‐ and corner‐sharing BiCl₇ units.     

Assessment of labelled products with different radioanalytical methods: study on 18F-fluorination reaction of 4-[18F]fluoro-N-[2-[1-(2-methoxyphenyl)-1-piperazinyl]ethyl-N-2-pyridinyl-benzamide (p-[18F]MPPF)

The serotonin receptor 5-HT_1A ligand 4-[¹⁸F]fluoro-N-[2-[1-(2-methoxyphenyl)-1-piperazinyl]ethyl-N-2-pyridinyl-benzamide (p-[¹⁸F]MPPF) was produced by a simplified method of Le Bars et al. Traditional oil bath heating was compared to microwave heating. Various radioanalytical methods, radio-Thin Layer Chromatography (TLC), High Pressure Liquid Chromatography (HPLC) and Mass Spectrometry (MS), were compared in the evaluation of the labelled product(s). The crude reaction mixture consisted of p-[¹⁸F]MPPF and 2–4 radioactive by-products eluting after the product fraction, and the reverse-phase HPLC method failed occasionally to separate p-[¹⁸F]MPPF from the radioactive by-product with close retention time. The heating method had no significant effect on the composition of labelled by-products. In LC-(ESI)-MS analysis of p-[¹⁸F]MPPF the labelled product was identified with m/z ratio of 435 ([M + H⁺]). The other HPLC fractions were measured to have following m/z ratios: (1) 327; 349; (675) (2) 402; 407/408; (791) and (3) 436, suggesting different kind of decomposition of the labelled product and/or the inactive precursor. The ion trap mass spectrometer was sufficient for the qualitative analysis of p-[¹⁸F]MPPF. However, differentiation of by-products arising from the decomposition of p-[¹⁸F]MPPF or from its precursor p-MPPNO₂ proved to be challenging.     

Gezielte Synthese von Kohlenwasserstoff-verbrückten Komplexen. Nucleophile addition von Pentacarbonylrhenat und -manganat an π-gebundene Dien-, Cyclodien-, Trimethylenmethan-, Cycloheptatrienyl- und Alkin-Liganden

Pentacarbonyl-rhenate and -manganate react with the cationic complexes [cpMo(CO)₂(diene)]⁺, [cpMo(CO)₂(cyclopentadiene]⁺, [cpMo(CO)₂(cyclohexadiene)]⁺, [cpMo(CO)₂(trimethylenemethane]⁺, [(OC)₃Mo(η⁷-C₇H₇)]⁺, [cp(OC)-(Ph₃P)Mo(alkyne)]⁺ to give the corresponding heteronuclear hydrocarbon-bridged complexes.     

Selen‐Polykationen stabilisiert durch polymere Chlorobismutat‐Anionen: Synthesen und Kristallstrukturen von Se4[Bi4Cl14] und Se10[Bi5Cl17]

Selenium Polycations Stabilized by Polymeric Chlorobismuthate Anions: Syntheses and Crystal Structures of Se₄[Bi₄Cl₁₄] and Se₁₀[Bi₅Cl₁₇] Reactions of selenium with selenium(IV) chloride and bismuth(III) chloride in sealed evacuated glass ampoules at temperatures between 110 and 155 °C yield a series of compounds which are composed of discrete selenium polycations and polymeric chlorobismutate anions. Besides the already known Se₈[Bi₄Cl₁₄] two new compounds have been identified by crystal structure analyses as Se₄[Bi₄Cl₁₄] (tetragonal, P4/n, a = 1089.1(2) pm, c = 993.7(2) pm, Z = 2) and Se₁₀[Bi₅Cl₁₇] (monoclinic, P2₁/c, a = 1079.24(8) pm, b = 2062.9(2) pm, c = 1676.1(2) pm, β = 90.87(1)°, Z = 4). Se₄[Bi₄Cl₁₄] was obtained as red transparent platelike crystals and is the first example of a compound with (chalcogen₄)²⁺ ions of exact square‐planar symmetry and molecular point group D_4h in the solid state. The cations are surrounded by layers of two‐dimensional polymeric anions [Bi₄Cl₁₄]^2–. Se₁₀[Bi₅Cl₁₇] forms dark grey crystals with a reddish luster. The structure contains the known bicyclic polycation Se₁₀²⁺ which is disordered over two positions and the first three‐dimensional polymeric chlorobismutate anion [Bi₅Cl₁₇]^2–. The different BiCl_x polyhedra are linked by sharing common vertices, edges, and faces.     

On the resonant behavior of the16O+15N reaction

The ¹⁶ O+ ¹⁵ N reaction products have been studied by the γ-ray detection method in the CM energy range 15.5 to 36.1 MeV and by the kinematical coincidence method at energies ranging from E _CM =20.6 to 33.5MeV. The γ-ray yield excitation function of the ¹⁶O 3^? inelastic channel shows the existence of resonant structures. Two structures with ～ 1.6 MeV width are observed in the large angle elastic scattering excitation function, they are correlated with the resonances seen in the inelastic channel. Angular momentum assignments were made from the elastic backward angular distributions.