Platinum complex catalyzed reaction of tributyltin cyanide with alkynes

In the presence of a catalytic amount (5 mol%) of a platinum complex, tributyltin cyanide (1) reacts with dimethyl- (2a) or diethyl acetylenedicarboxylate (2b) to afford cyanostannylation adducts (3a, b) in excellent yields. The reaction proceeds highly selectively affording only a (Z)-isomer. The compounds 3a, b are novel products which possess synthetically useful cyano, alkenylstannyl and alkoxycarbonyl functionalities in the same molecule. Two alkoxycarbonyl functionalities may be indispensable on each alkyne carbon to accomplish the cyanostannylation reaction. Reaction with terminal alkynes gave the stannylated product (6).     

丙烯酸甲酯与N-对卤苯基甲基丙烯酰胺共聚合的研究

<正> 我们已经报道过甲基丙烯酸甲酯与N-对卤苯基甲基丙烯酰胺共聚合的研究。本文工作合成了丙烯酸甲酯与N-对卤苯基甲基丙烯酰胺共聚体,研究了这二组共聚体系的聚合反应、共聚体的组成、估算了单体的竞聚率,比较了这两种酰胺对丙烯酸甲酯与甲基丙烯酸甲酯的反应活性。     

Novel Poly(ethylene glycol)s Bearing Tributyltin Carboxylate End Groups as Ionophores in the Development of Chloride Ion‐Selective Electrodes

The potentiometric response characteristics of electrodes based on PVC membranes containing novel polyethylene glycols (PEGs) with tributyltin carboxylate end groups as ionophores for chloride ions were studied in 0.1 M HEPES solution, at the spontaneous pH. The effects of solvent mediator, amount of cationic additive, amount of ionophore and PEG chain length on the behavior of the sensors were investigated. The membranes with the best composition responded to chloride concentration in a linear range from 10^?4 to 10^?1 M Cl^? with a nearly Nernstian slope and a detection limit of 6.5×10^?5 M. The sensor showed a short response time (<25 s) in the whole concentration range and an operational lifetime of about one week for the most performing PVC membranes. In comparison with ISEs based on anion exchangers the interferences from the more lipophilic anions were greatly reduced, as inferable by the selectivity coefficients determined with the matched potential method at chloride concentration of 3.0×10^?3 M.     

Tributyltin hydride-mediated cyclisations of cinnamic enamides to piperidin-2-ones or pyrrolidin-2-ones. Indolizidinone ring formation by tandem radical cyclisation

Efficient 6-endo-trig free radical cyclisations of various 3-phenyl-acryl enamides to piperidin-2-ones, by using Bu₃SnH and AIBN in boiling toluene, are reported. A different result has been observed for related enamide system without phenyl substituent at the 3-position of an acrylic moiety, as such a reaction of 3-methyl-butenoic acid cyclohex-1-enyl-methyl-amide afforded only the 5-exo-trig product. The difference in the cyclisation mode has been explained in terms of a reversible process leading to the thermodynamically more stable product. An application of this method for the tandem cyclisation permits to obtain idolizidine derivatives.     

Interdisciplinary study for the evaluation of biochemical alterations on mussel <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis> exposed to a tributyltin-polluted area

An interdisciplinary approach was employed to monitor the concentration and the effects of butyltin compounds in mussels (Mytilus galloprovincialis). Tissues from animals exposed to a marine area (Vado Ligure harbour) with a high concentration of tributyltin (TBT) were analysed and compared with control samples. TBT concentrations were measured by gas chromatography–mass spectrometry and the protein pattern in gill tissues was studied by proteomic analysis. Several proteomic signatures associated with contaminant exposure were observed; spots that were significantly increased in all contaminated samples were identified by mass spectrometry as fragments of β-tubulin. The degradation of β-tubulin was then confirmed by western blot analysis with specific anti-β-tubulin antibody. The effects observed on mussel gills after exposure in the TBT-polluted area are discussed.     

Synthesis of a Novel pH-Sensitive Methacrylate Amphiphilic Polymer and Its Primary Application in Aqueous Two-phase Systems

In this study, a novel pH-sensitive and reversible water-soluble polymer(P(ABC)) forming aqueous two-phase systems(ATPS) was synthesized by using 2-(dimethylamino)ethyl methacrylate, t-butyl methacrylate, and methyl methacrylate as monomers and 2,2'-azo-bis-isobutyronitrile as initiator. The P(ABC) could be recovered by adjusting isoelectric point (PI) to 8.4, and recovery at PI could reach 95%. ATPS was formed by 5% (w/w) P(ABC) and 10% (w/w) PEG20000. The partition coefficient K of lysozyme was 6.8, and the partition coefficient K of bovine serum albumin could reach 12.5 in the ATPS.     

Preparation and characterisation of poly(high internal phase emulsion) methacrylate monoliths and their application as separation media

Poly(glycidyl methacrylate-co-ethyleneglycol dimethacrylate) monolithic supports were prepared by radical polymerisation of the continuous phase of water in oil high internal phase emulsions. Morphology of monolithic materials was studied by scanning electron microscopy and mercury intrusion porosimetry. The ratio of phase volume and the degree of crosslinking influenced the void size and pore size distribution of resulting polymers. Void sizes between 1 and 10 microm were observed and average pore sizes around 100 nm. Polymers with 60, 75, 80 and 90% pore volume were prepared and even samples with highest pore volume showed good mechanical stability. They were modified to bear weak-anion exchange groups and tested on the separation of standard protein mixture containing myoglobin, conalbumine and trypsin inhibitor. Good separation was obtained in a very short time similar to the separation obtained by commercial methacrylate monoliths. However, higher dispersion was observed. Bovine serum albumin dynamic binding capacity for monolith with 90% porosity was close to 9 mg/ml.     

Determination of tributyltin in marine sediment: Comité Consultatif pour la Quantité de Matière (CCQM) pilot study P-18 international intercomparison

The capabilities of National Metrology Institutes (NMIs—those which are members of the Comité Consultatif pour la Quantité de Matière (CCQM)of the CIPM) and selected outside "expert" laboratories to quantitate (C₄H₉)₃Sn⁺ (TBT) in a prepared marine sediment were assessed. This exercise was sanctioned by the 7th CCQM meeting, April 4–6, 2001, as an activity of the Inorganic Analysis Working Group and was jointly piloted by the Institute for National Measurement Standards of the National Research Council of Canada (NRC) and the Laboratory of the Government Chemist (LGC), UK. A total of 11 laboratories submitted results (7 NMIs, and 4 external labs). Two external laboratories utilized a standard calibration approach based on a natural abundance TBT standard, whereas all NMIs relied upon isotope dilution mass spectrometry for quantitation. For this purpose, a species specific ¹¹⁷Sn-enriched TBT standard was supplied by the LGC. No sample preparation methodology was prescribed by the piloting laboratories and, by consequence, a variety of approaches was adopted by the participants, including mechanical shaking, sonication, accelerated solvent extraction, microwave assisted extraction and heating in combination with Grignard derivatization, ethylation and direct sampling. Detection techniques included ICP–MS (with GC and HPLC sample introduction), GC–MS, GC–AED and GC–FPD. Recovery of TBT from a control standard (NRCC CRM PACS-2 marine sediment) averaged 93.5±2.4% (n=14). Results for the pilot material averaged 0.680±0.015 µmol kg^–1 (n=14; 80.7±1.8 µg kg^–1) with a median value of 0.676 µmol kg^–1. Overall, performance was substantially better than state-of-the-art expectations and the satisfactory agreement amongst participants permitted scheduling of a follow-up Key comparison for TBT (K-28), a Pilot intercomparison for DBT (P-43), and certification of the test sediment for TBT content and its release as a new Certified Reference Material (HIPA-1) with a TBT content of 0.679±0.089 µmol kg^–1 (expanded uncertainty, k=2, as Sn) (80.5±10.6 µg kg^–1).Electronic Supplementary Material Supplementary material is available in the online version of this article at .     

大孔网状树脂对三丁基氯化锡的吸附特性研究

从热力学，动力学及柱上吸附三方面讨论了Ｘ－５大网树脂对三丁基氯化锡的吸附特性。结果表明，吸附剂的吸附过程以物理吸附为主，外表面，内表面的吸附率分别为３８％，６２％装柱动态吸附率主要取决于柱长及流速，而溶液盐度及ｐＨ值影响不大。     

微柱高效液相色谱与火焰光度检测器联用研究

报道了微柱高效液相色谱（micro-column HPLC）与火焰光度检测器（FPD）在线联用系统的研究,目的是发展一种不经复杂前处理步骤即可直接测定有机锡化合物的方法。三丁基锡氯化物（TBT）等经HPLC微柱分离后,通过毛细管连接引入特制的燃烧头,通过火焰光度检测器进行检测,对系统有关参数进行了优化和讨论。所建方法可以直接测定各种水样中的三丁基锡氯化物。