淀粉/AMPS/DMC高吸水树脂的合成及对重金属离子的吸附性能

以可溶性淀粉、2-丙烯酰胺-2-甲基丙磺酸(AMPS)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺(NMBA)作交联剂,采用水溶液聚合法,合成了一种新型淀粉/AMPS/DMC高吸水树脂。通过红外光谱、扫描电镜和热重分析确定了所合成高吸水树脂的结构组成,并研究了其对Cu~(2+)、Ni~(2+)两种重金属离子的吸附能力。结果显示,淀粉/AMPS/DMC高吸水树脂对于CuSO_4和NiSO_4的吸附极限浓度均为2g/L,均在2~3 min内吸附完全,其等温吸附行为符合Freundlich方程。     

聚苯乙烯基N,O-二酰基磺酰羟胺树脂: 一种双酰基转移试剂在合成酰胺库中的应用

用聚苯乙烯基磺酰羟胺树脂1与酰氯2反应合成了聚苯乙烯基N,O-二酰基磺酰羟胺树脂3. 树脂3作为一种新的双酰基转移试剂可与胺4发生酰基转移反应, 合成了含有24个结构类似的酰胺化合物库. 改变酰氯的种类, 结果发现双对硝基苯甲酰树脂3a的活性较高. 双酰基树脂3胺解结果表明, 由脂肪族胺得到的酰胺收率较芳香族胺高. 当解脱试剂同时含有羟基和氨基时, 双酰基树脂3能选择性地在氨基端发生酰基转移, 而羟基端不受影响.     

The cis chlorination of alkenes using selenium reagents

The phenylselenenyl chloride adduct from alkenes can be oxidised and the selenomoiety can be displaced by chloride to give high yields of dichlorides with cis geometry.     

Synthesis of cyclic peptides via O-N-acyl migration

We describe here a novel and convenient synthesis of head-to-tail cyclic peptide avoiding racemization. Linear depsipeptides including a serine residue as the key element for ester bond formation and acyl transfer were synthesized on 2-chlorotrityl chloride resin. After cleavage from the resin, intramolecular head-to-tail cyclization was performed in solution by C-terminal activation of urethane protected O-acyl serine residue. After removal of the N^α-serine protecting group, the final step consisted in O-N-acyl migration reaction on the ‘switch’ or ‘click’ element to restore native cyclic peptides.     

载氯化碘Lin树脂的制备及其对活泼芳香化合物的碘化研究

聚合物Lin树脂与氯化碘作用得到载氯化碘Lin树脂。室温及CaCO3或NaHCO3存在下,该树脂在CH2Cl2和CH3OH溶液中,使芳胺、乙酰芳胺和酚碘化为相应的1-碘取代芳香化合物,产率为80.5%～94.0%。该树脂是一种反应条件温和,选择性好的活泼芳环碘化剂。Lin树脂可再生重复使用。     

N-烷基-N-酰基磺酰胺聚苯乙烯基微球作为固相酰化剂的研究

一种可循环使用的固相试剂：N-烷基-N-酰基磺酰胺聚苯乙烯基微球(5), 通过对聚苯乙烯磺酰氯微球树脂进行两步功能基化的修饰反应来制备. 制备过程如下：聚苯磺酰氯树脂(1)与伯胺(2)反应得到聚苯乙烯基N-烷基磺酰胺树脂(3), 树脂3用酰氯(4)或酸酐酰化得到N-烷基-N-酰基磺酰胺聚苯乙烯基树脂(5). 酰化的树脂5作为酰基转移试剂与亲核试剂胺反应得到二级酰胺. 根据5上取代基对酰胺生成的程度的影响结果表明, 烷基R¹和酰基(R²CO)对酰基转移反应活性的大小依次分别为：苯基＞苄基＞甲基＞正丁基＞＞H和对硝基苯甲酰基(苯甲酰基＞乙酰基. 胺的亲核能力对酰胺的收率也有一定的影响. N-苯基-N-苯甲酰基磺酰胺树脂重复使用3次没有发现活性降低.     

三聚硫氰酸交联聚氯乙烯树脂的合成及其对Cu~(2+)的吸附性能

以三聚硫氰酸为原料,邻苯二甲酸二辛酯(DOP)为增塑剂,聚氯乙烯为大分子骨架,在MgO的存在下,合成得到了三聚硫氰酸交联聚氯乙烯树脂.对交联树脂吸附重金属离子的性能研究表明,合成树脂对Cu2+的吸附容量及选择性最大,在实验条件下吸附量达到1.056mmol/g;对其他金属离子吸附量很小,甚至不吸附.     

A method for the replacement of 137Cs with 40K as a non-hazardous radioactive tracer for open-source decommissioning research applications

The potential of ⁴⁰K as a radioactive tracer analogue of ¹³⁷Cs in ion exchange experiments is reported. Solutions of varying concentrations of potassium chloride (KCl) have been monitored radiometrically in a sodium iodide well-counter to determine the activity-concentration relationship. Ion exchange reactions using an exemplar ion exchange resin, KCl and non-radioactive caesium chloride (CsCl) solutions have been studied radiometrically. The adsorbed amounts of potassium and caesium are observed, inferred from displaced K⁺ ions, to be consistent with the total exchange capacity of the resin. Adsorption isotherm models have been applied to the experimental data, with the Freundlich isotherm observed to fit the data with the highest degree of consistency. The reported results indicate that decontamination techniques involving hazardous isotopes of anthropogenic origin such as ¹³⁷Cs can be developed, evaluated and optimised by substituting a chemically and physically similar non-hazardous radioactive isotope, in this case ⁴⁰K. This represents a means by which innovative decontamination techniques and regimes might be identified without the need to use ¹³⁷Cs and thus avoids additional generation of radioactive wastes.     

SOLID PHASE SYNTHESIS OF ISOXAZOLINES

1. INTRODUCTION A solid phase organic synthesis (SPOS) has increasingly attracted chemist抯 attention over the past decades [1~3]. It was found that the compounds with biological activity are mostly derived from heterocycle structures. It is therefore no…     

SOLID PHASE SYNTHESIS OF ISOXAZOLINES

The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin isreported. 2-Polystyrylsuifonamidoethanol resin 1 was reacted with acryloyl chloride to afford2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominatedaldoximes by [3+2] cycioaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6mol/L HCI solution to obtain isoxazolines in good yield and purity.     

Preparation of Polystyrene-supported N-phenyl-N-acyl Sulfonamide Resin and its Application in Solution-phase Synthesis of Amides

Polystyrene-supported N-phenyl-N-acyl sulfonamide resin was prepared by reacting polystyrene sulfonyl chloride resin with aniline and acylating in pyridine with either acid chlorides or anhydrides. Then, this resin was utilized as a new type of acyl transfer reagent to synthesize the amide library. It was approved to be a more effective acyl transfer reagent with higher amide yields than the polystyrene-supported N-methyl-N-acyl sulfonamide resin and N-benzyl-N-acyl sulfonamide resin. When the phenyl group bonded to the N atom on N-phenyl-N-acyl sulfonamide resin was substituted by the electron withdrawing group or electron donating group, a decreasing amide yield was obtained. N-phenyl-N-acyl sulfonamide resin could be regenerated many times.     

超支化聚酯的改性及其结晶性能的研究

用十六酰氯和十八异氰酸酯分别对端羟基的超支化聚酯Boltorn^TMH20改性,可获得粉末状超支化低聚物,具有无定形“内核”及可结晶“外壳”的分子结构.实验结果表明,采用十八异氰酸酯改性的丙烯酸化超支化聚酯的熔点高于十六酰氯改性聚合物.     

Determination of nitrite and bromate in disinfected water samples at the low μg/L level by means of a high-capacity anion exchanger

Bromate and nitrite are formed during the disinfection of water. The German threshold value for nitrite in drinking water is 100 μg/L, for bromate a limit below 50 μg/L has to be established. A self-made high-capacity resin with 2-(dimethylamino)-ethanol functionality in combination with a UV-transparent elution system based on perchloric acid allows the separation and sensitive photometric detection of nitrite and bromate, even if high chloride concentrations are present. The high capacity of the strongly basic resin allows sample volumes of up to 400 μL without disturbance of the separation. Detection limits for bromate and nitrite are 15 and 10 μg/L, respectively. The direct analysis of water samples with high salt contents, such as disinfected pool water, is possible by insertion of an on-line chloride removal step. Received: 30 September 1996 / Revised: 20 December 1996 / Accepted: 28 December 1996     

Polystyrene‐modified novolac epoxy resin/clay nanocomposite: Synthesis,and characterization

A polystyrene‐modified epoxidized novolac resin/montmorillonite nanocomposite was fabricated and characterized successfully. For this purpose, novolac resin (NR) was epoxidized through the reaction of phenolic hydroxyl group with epichlorohydrin in super basic medium to produce epoxidized novolac resin (ENR). Afterward, a polystyrene was synthesized by atom transfer radical polymerization (ATRP) technique, and then brominated at the benzylic positions using N‐bromosuccinimide (NBS). The brominated polystyrene (PSt‐Br) was reacted with ethanolamine in basic medium in order to afford an amine‐functionalized polystyrene (PSt‐NH₂). An organo‐modified montmorillonite (O‐MMT) was synthesized through the treatment of MMT with hexadecyl trimethyl ammonium chloride salt. Finally, ENR‐PSt/MMT nanocomposite was fabricated through curing a mixture of ENR (70 wt.%) and O‐MMT (5 wt.%) with PSt‐NH₂ (25 wt.%). Transition electron microscopy (TEM) and powder X‐ray diffraction (XRD) analysis revealed that the fabricated nanocomposite has an exfoliated structure. Thermal property studies using thermogravimetric analysis (TGA) showed that the curing of ENR by PSt‐NH₂, as well as incorporation of a small amount of MMT have synergistic effect on the thermal stability of the ENR resin.     

Traceless solid-phase synthesis of 1,4-disubstituted-6-nitro-3,4-dihydro-1H-quinoline-2-ones

A traceless solid-phase route to 1,4-disubstituted-6-nitro-3,4-dihydro-1H-quinazolin-2-ones is described. N-Alloc-3-amino-3-(2-fluoro-5-nitrophenyl)propionic acid was tethered to Rink resin via its carboxylic group. The protected amine was coupled with an organic acid after Alloc-deprotection and the arylfluorine was displaced with a primary amine to generate a resin-bound aniline with two diversity points. The aniline was released via cleavage to produce the desired products in high yield and purity.     

Development of a new linker for the solid-phase synthesis of N-hydroxylated and N-methylated secondary amines

Merrifield resin was modified by the introduction of an ortho-nitrophenylethanal group that served as a linker moiety to attach amines to the resin by reductive amination. Resin-bound tertiary amines were shown to be readily transferred into the respective liberated N-hydroxylated or N-methylated derivatives by either an oxidation/Cope elimination or a permethylation/Hofmann elimination protocol. With these two divergent liberation/derivatization options, the new resin offers new flexibility in the solid phase synthesis of N-modified secondary amines, for instance in spider toxin synthesis.     

Investigation of hydrolysed TaCl5-graphite intercalation compounds with PIXE

Graphite intercalation compounds combine low density with high electrical conductivity. These physical properties makes these compounds interesting as components of carbon epoxy composites, but the high reactivity of graphite intercalation compounds to moisture is an obstacle for practical applications.Earlier investigations showed that tantalum chloride forms with graphite flakes an intercalation compound, which is stable against humidity for a few days. We studied the stability against moisture of a stage-2 tantalum chloride intercalation compound after one year. A fresh tantalum chloride intercalation compound was exposed for 2 h in water and afterwards stored at room humidity for ca. 1 year. Some of the flakes were embedded in epoxy resin after a few months. After 1 year all flakes were highly altered. The non-embedded flakes showed coatings of tantalum oxide on the surface. The epoxy-resin-mounted flakes showed an irregular surface with many cracks. The edges of the flakes were sealed by epoxy resin, whereas the basal planes of the flakes are not coated. With particle-induced X-ray emission (PIXE) we performed Ta and Cl analyses across the flakes. The ClTa ratios varied over a wide range and, especially near the cracks, were very low. In other regions of the flake we found that tantalum oxychloride or a mixture of tantalum chloride and tantalum oxide had been formed. In a few regions we found evidence that tantalum chloride was encapsulated in the interior of the flakes.     

Synthesis of the hydrophobic–hydrophilic macroporous poly divinylbenzene/poly(sodium acrylate) IPN resin and adsorption performance for berberine

The macroporous polydivinylbenzene/poly(methyl acrylate) interpenetrating polymer network (PDVB/PMA IPN) was prepared by the sequential suspension polymerization method, and was modified to be hydrophobic–hydrophilic macroporous polydivinylbenzene/poly (sodium acrylate) IPN (PDVB/PNaA IPN) by converting the PMA to PNaA under the condition of base. The effects of different mass ratio of the two networks and different cross‐linking degree of the second network on the pore structure and adsorption capacity of PDVB/PNaA IPN resin were studied. The PDVB/PNaA IPN resin whose adsorption quantity is the biggest was chosen to study further. The pore structure, the weak acid exchange capacity, the water retention capacity, and the swelling ability of PDVB/PNaA IPN resin were measured. The study focused on the adsorption isotherms of berberine at different temperatures. Isosteric adsorption enthalpy, adsorption Gibbs free energies can be calculated according to thermodynamic functions. The results show that the saturated adsorption quantity of berberine is up to 109.4 mg ml^?1 (wet resin) by the way of dynamic adsorption and desorption experiment. The resin could be reused by the mixture with 0.5% sodium chloride and 80% ethanol. On the one hand the hydrophobic PDVB in the PDVB/PNaA IPN resin has the ability of adsorption using π–π interaction, and on the other hand the hydrophilic PNaA in the PDVB/PNaA IPN resin has the ability of adsorption using ion exchange interaction. An important conclusion can be drawn that the PDVB/PNaA IPN resin has a promising application prospect in extracting and separating quaternary ammonium type alkaloids such as berberine. Copyright © 2009 John Wiley & Sons, Ltd.     

N-2-氯苄基苯甲酰胺的固相合成及其晶体结构分析

N-2-氯苄基苯甲酰胺采用固相法制备.聚苯乙烯磺酰氯(1)在吡啶存在下与2-氯苄胺反应得到N-2-氯苄基磺酰胺树脂(2),进一步在吡啶催化下用苯甲酰氯进行酰化得到N-2-氯苄基-N-苯甲酰基磺酰胺树脂(3).用TiCl₄/Zn/THF试剂处理,从树脂3上解脱得到产物N-2-氯苄基苯甲酰胺(4),产率92%.N-2-氯苄基苯甲酰胺的晶体属于单斜晶系,P2₁空间群,晶胞参数:a=0.7149(3)_nm,b=0.8772(4)_nm,c=0.9704(4)_nm;β=95.172(7)°;晶体结构中存在两种分子间氢键相互作用.     

Grafting of Polymers onto a Crosslinked Polymer Carrying Carboxyl Groups as a Model Compound for Carbon Black

Abstract

A cation-exchange resin (a crosslinked polymer carrying carboxyl groups) was used as a model compound for carbon black, and the grafting of several polymers to the resin was investigated. Reaction of acyl chloride groups that had been placed on the ion-exchange resin with polymers having hydroxyl or amino groups, such as polypropylene glycol, polyethylene glycol, polybutadiene glycol, polyvinyl alcohol, silicone diol, silicone diamine, and polyethyleneimine, resulted in grafting to the ion-exchange resin. In further experiments, primary amino groups were placed on the cation-exchange resin by reaction of acyl chloride groups with ethylenediamine. It was found that ring-opening polymerization of γmethyl L-glutamate N-carboxyanhydride is initiated by the amino groups on the resin, and polypeptide was grafted from the cation-exchange resin. Therefore, the reactivity of carboxyl groups on the resin was found to be similar to that on carbon black. However, carboxyl groups on the resin failed to initiate the cationic polymerization of vinyl monomers, in contrast to those on carbon black. This suggested that the acidity of carboxyl groups on carbon black is greater than on the cation-exchange resin.