Generalization of in-situ polymerization method for preparing core-shell polymeric nanospheres and hollow spheres

According to the new method of preparing core-shell nanospheres developed by our group, by using two monomers, 2-hydroxypropyl methacrylate(HPMA) and vinyl acetate(VAc), two kinds of core-shell nanospheres with poly(ɛ-caprolactone) (PCL) as the core and crosslinked poly(2-hydroxypropyl methacrylate) (PHPMA) or poly(vinyl acetate) (PVAc) as the shell were successfully prepared under similar conditions. After degrading the PCL cores of the two kinds of nanospheres by lipase, the corresponding crosslinked poly(methyl acrylic acid) hollow spheres and crosslinked poly(vinyl alcohol) hollow spheres were obtained. Results indicate that the new method we proposed for preparing core-shell polymeric nanospheres via in-situ polymerization can be generalized to a certain extent, and it is suitable for many systems provided the monomer used is soluble in water, while its corresponding polymer is insoluble in water. Translated from Chemical Journal of Chinese University, 2006, 27(9): 1762–1766 [译自: 高等学校化学学报]     

一种纳米蜡乳液的制备及应用研究

研究了一种纳米蜡乳液的制备方法。通过测试证明该体系稳定,得到平均粒径为57.6nm大小的纳米蜡乳液,可代替各种行业中使用的普通蜡乳液,如皮革[1]、纺织[2]、造纸[3][4]等行业·     

Tetraarylester der μ-Imidodiphosphorsäure und ihre Thioderivate — Strukturuntersuchungen

Tetraarylesters of μ-Imido-Diphosphoric Acid and its Thio Derivatives — Structure Investigations New O,O′,O″,O?-tetratolyl- and ditolyl-diphenylesters of the μ-imido-diphosphoric acid and its mono and dithio derivatives were synthesized, compared with the corresponding tetraphenylesters and investigated by ¹H, ¹³C, and ³¹P NMR spectroscopy and X-ray crystal structure analysis. Structures of the O,O′,O″,O?-tetrakis-(2-methyl-phenyl)-μ-imidodiphosphate, 1b , as well as of the corresponding ortho-, meta- and para-tolylesters of the μ-imido-monothiodiphosphoric acid ( 2a , 2b , 2c ) were determined. All the compounds form dimers via N? H…?O hydrogen bonds in the crystal as well as in nonpolar solvents. The distances around the phosphorus atoms rise with decreasing electronegativity of the phosphorus substituents. Signs of the ²J_{P? N? P} coupling constants were determined by ¹³C{¹H, ³¹P} triple resonance experiments for some compounds. These constants become more negative owing to substitution of a phosphoryl by a thiophosphoryl group.     

Determination of paraquat in human blood plasma using reversed-phase ion-pair high-performance liquid chromatography with direct sample injection

This report describes the determination of paraquat (PQ) in human blood plasma samples by a direct-injection reversed-phase ion-pair chromatographic method. Blood plasma filtrate was injected directly into the LiChrospher® RP-18 alkyl-diol silica (ADS) precolumn integrated in a column switching system using a mixture of 3% 2-propanol and 10 mM sodium octane sulfonate (SOS) in a 0.05 M phosphate buffer (pH 2.8). After washing with this phase, the ADS precolumn was back-flushed with the analytical mobile phase consisting of 40% of methanol and 10 mM SOS in a 0.05 M phosphate buffer (pH 2.8) at a flow rate of 1.0 ml min⁻¹, in order to carry the analyte to a conventional reversed-phase analytical column, where the separation of PQ was achieved and finally detected by UV at 258 nm. The recoveries of PQ from human blood plasma samples ranged between 95.0 and 99.5% at nine different concentrations (from 0.05 to 3.00 μg of PQ ml⁻¹) with coefficients of variation <2.5% (n=3). The precision expressed as relative standard deviation was below 3.5% for between-day and below 4.3% for within-day measurements (n=5). The detection limit (signal-to-noise ratio, S/N>3) was 0.005 μg ml⁻¹ with an injection volume of 200 μl. The proposed method is promising for the identification and quantification of PQ at low concentration levels and is suitable for its analysis in human blood plasma samples from intentional or accidental poisonings cases with a sample throughput of 5 samples per hour.     

Regioselective 2 A -2 D -Disulfonylations of Cyclodextrins for Practical Bifunctionalization on the Secondary Hydroxyl Face

A useful technique to bifunctionalize the secondary hydroxyl faces of cyclodextrins is described. Regioselective2^A,2^D-disulfonylations ofcyclodextrins were achieved by reacting cyclodextrins with a combinationof a novel disulfonyl imidazole reagent and molecular sieves inN,N-dimethylformamide. The resulting disulfonates were convertedto 2^A,3^A,2^D,3^D-dimannoepoxy-cyclodextrins and3^A,3^D-diamino-3^A,3^D-dideoxy-(2^AS,3^AS),(2^DS,3^DS)-cyclodextrins, which contain twofunctional groups on the periphery of the molecules.     

氯化钪-氯化钠-氯化钾熔盐制备新工艺研究

研究了以Sc2O3为原料，盐酸回流溶解后与NaCl，KCl，NH4Cl溶液混合，经蒸发浓缩、结晶、真空预脱水，再在氩气保护下分段升温脱水、升华除去过量NI-hCl后制备ScCl3-NaCl-KCl熔盐的新工艺。研究表明，添加NH4Cl后加热脱水时，NH4Cl分解产生的HCl气体能抑制ScCl3水合物加热过程中的水解，溶解产生的水不溶性钪，从而有效地防止了Sc2O3等水不溶化合物的生成。制备的ScCl3-NaCl-KCl熔盐脱水完全、水不溶性钪含量很低，能满足熔盐金属热还原法制备金属钪及铝钪中间合金对熔盐原料的要求。     

植物样品中单宁的微波溶出快速测定法研究

研究了利用微波代替一般的沸水浴处理试样的方法。对不同植物样品中单宁的浸提测定，与常规方法做了对照，并讨论了微波功率、时间、酸度等因素对测定结果的影响。研究表明，此法可大大地缩短测定时间，提高测定效率，节省人力、物力，不污染环境，便于大批量样品的测定，相对标准偏差≤１．４％，测定结果较为满意。为植物样品中单宁的测定，提供了一个快速、简便、准确的分析方法，并可借鉴于其它样品的测定。     

[Rb2(H2O)2][Re3(μ-Cl)3Br7(H2O)2]2 · H2O,ein gemischtes Halogenid-Hydrat mit anionischen Dimeren {[Re3(μ-Cl)3Br7(H2O)2]2 · H2O}2−

[Rb₂(H₂O)₂][Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O, a Mixed Halide-Hydrate with the Anionic Dimer {[Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O}^2? [Rb₂(H₂O)₂][Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O crystallizes as dark redbrown single crystals from an hydrobromic-acid solution of ReCl₃ and RbBr at 0°C. An important feature of the crystal structure (monoclinic, C2/c; a = 1494.61(8); b = 835.71(4); c = 3079.96(19) pm; β = 97.801(4)°; V_m = 573.9(4) cm³mol^?1; R = 0.060; R_w = 0.038) is the connection of two anions [Re₃(μ-Cl)₃Br₇(H₂O)₂]^? via a water molecule to dimers, {[Re₃(μ-Cl)₃Br₇(H₂O)₂]₂ · H₂O}^2?. These dimeric units are contained in slabs that are stacked in the [001] direction and held together by Rb⁺ cations and crystal water.     

Preparation and crystal structure of Guanidinium Cyclododecaphosphate Telluric Acid Hydrate: [C(NH2)3]12P12O36 · 12 Te(OH)6 · 24H2O

The title compound ist the first example of an adduct between telluric acid and the twenty four membered ring anion of a cyclododecaphosphate. [C(NH₂)₃]₁₂P₁₂O₃₆ · 12 Te(OH)₆ · 24 H₂O crystallizes trigonal (rhomboedral: R3) with Z = 3 and the unit-cell dimensions a = 15.854(9), c = 51.26(2) Å in the hexagonal setting. The crystal structure was solved by direct methods and refined to a final R value of 0.031. It is characterized by a succession of three different typs of alternating layers perpendicular to the c direction. This layers are connected only by hydrogen bonds. The individual layers are built up of A: P₁₂O₃₆ anions, guanidinium cations and water of crystallisation, B: hexagonal arranged Te(OH)₆ groups and guanidinium cations and C: water of crystallization.     

Neue Rheniumkomplexe mit Trichalkogenido- und Tetrachalkogenido-Chelatliganden

New Rhenium Complexes Containing Trichalcogenido and Tetrachalcogenido Chelate Ligands The reactions of Cp*ReCl₄ with polychalcogenide salts such as Na₂S₄ or (NEt₄)₂Se₆ lead initially to the violet trichalcogenido chelate complexes Cp*ReCl₂(E₃) (E = S ( 3a ), Se ( 3b )) which, due to their functional chloro ligands, can be used as intermediates for further reactions. Upon hydrolysis in moist solvents or aminolysis with tert. butylamine 3a, b are converted into the tetrachalcogenido chelate complexes Cp*Re(O)(E₄) (E = S ( 4a ), Se ( 4b )) and Cp*Re(N^tBu)(E₄) (E = S ( 5a ), Se ( 5b )), respectively. X-Ray structure analyses were carried out for the three mononuclear cyclo-oligoselenido compounds 3b–5b . It appears that the size of the Se^2?_n chelate ring (n = 3 or 4) essentially depends on steric factors within the coordination sphere of rhenium.