Synthesis and Crystal Structure of Bis(nitrate)bis(N-n-octyl-α-pyrrolidone)uranyl (II)

1 INTRODUCTION Tri-butyl phosphate (TBP) has been widely used for the extraction reagent in Th-U fuel to separate uranium from thorium. However di-butyl phosphate (DBP) and butyl phosphate (MBP), the radiolytic products of TBP, exhibit some coordinated ability to the fission elements, such as Zr and Nb. The physical and chemical properties of amides and caprolactam are similar to those of TBP, and they selectively extract U(VI) and Th(VI). The principal advantages of amides an…     

Selective separation and enrichment of proteins in aqueous two-phase extraction system

A simple aqueous two-phase extraction system(ATPS) of PEG/phosphate was proposed for selective separation and enrichment of proteins.The combination of ATPE with HPLC was applied to identify the partition of proteins in two phases.Five proteins (bovine serum albumin,Cytochrome C,lysozyme,myoglobin,and trypsin) were used as model proteins to study the effect of phosphate concentration and pH on proteins partition.The PEG/phosphate system was firstly applied to real human saliva and plasma samples,some pro...     

掺杂双(N-2-甲基苯基-水杨醛亚胺)合铜(II)配合物的碳糊电极电催化测量过氧化氢(英文)

The electrochemical behavior of a bis (N-2-methylphenyl-salicyldenaminato)copper (II) complex spiked in a carbon paste electrode (BMPSCu-CPE) and its electrocatalytic reduc-tion of H2 O2 were examined using cyclic voltammetry, chronoamperometry, and differen-tial pulse voltammetry. Cyclic voltammetry was used to study the redox properties of BMPSCu-CPE at various potential scan rates. The apparent charge transfer rate constant and the transfer coefficient for the electron transfer between BMPSCu and the carbon paste electrode (CPE) were 1.9 ± 0.1 s–1 and 0.43, respectively. BMPSCu-CPE had excel-lent electrocatalytic activity for H2 O2 reduction in 0.1 mol/L phosphate buffer solution (pH 5.0), and it decreased the overpotential by 300 mV as compared to CPE alone. The diffusion coefficient and kinetic parameters such as the heterogeneous catalytic electron transfer rate constant and electron transfer coefficient for the reduction of H2 O2 at the BMPSCu-CPE surface were also determined using electrochemical methods. Differential pulse voltammetry showed two linear dynamic ranges of 1.0–10.0 and 10.0–300.0 μmol/L and a detection limit of 0.63 μmol/L H2 O2. The BMPSCu-CPE has excellent repro-ducibility and long term stability, and it was successfully applied for the determination of H2 O2 in two pharmaceutical samples: an antiseptic solution and a hair dying cream.     

Mechanism of gold solvent extraction from aurocyanide solution by quaternary amines: models of extracting species based on hydrogen bonding

The mechanism of gold solvent extraction from KAu(CN)2 solution was investigated by means of FTIR, EXAFS, ICP and radioactive tracer methods. Two extraction systems were studied, namely N263-tributyl phosphate(TBP)-n-dodecane and N263-iso-octanol-n-dodecane. High-resolution FT IR spectroscopy indicated that the CN stretching vibrations of the two extraction systems differred greatly. In order to interpret the significant difference in CN stretching vibrations, two extracting species models are proposed——supramolecular structures based on the formation of hydrogen bonds between Au(CN)2- and modifiers such as TBP and iso-octanol.     

用聚(L-蛋氨酸)/纳米金修饰玻碳电极同时灵敏检测多巴胺和尿酸(英文)

A novel electrochemical sensor was fabricated by electrodeposition of gold nanoparticles on a poly(L-methionine)(PMT)-modified glassy carbon electrode(GCE) to form a nano-Au/PMT composite-modified GCE(nano-Au/PMT/GCE).Scanning electron microscopy and electrochemical techniques were used to characterize the composite electrode.The modified electrode exhibited considerable electrocatalytic activity towards the oxidation of dopamine(DA) and uric acid(UA) in phosphate buffer solution(pH = 7.00).Differential pulse voltammetry revealed that the electrocatalytic oxidation currents of DA and UA were linearly related to concentration over the range of 5.0 ×10–8 to 10–6 mol/L for DA and 7.0 × 10–8 to 10–6 mol/L for UA.The detection limits were 3.7 × 10–8mol/L for DA and 4.5 × 10–8 mol/L for UA at a signal-to-noise ratio of 3.According to our experimental results,nano-Au/PMT/GCE can be used as a sensitive and selective sensor for simultaneous determination of DA and UA.     

磷酸锆铁催化无溶剂条件下醇和苯酚乙酰化(英文)

Iron zirconium phosphate(ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various sub-strates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3  when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environ-mentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.     

CHROMATOGRAPHIC SEPARATION ON GRAPHITE OF FULLERENE-C_(60) AND-C_(70)

The mixture of fullerene—C_(60) and —C_(70) was successfully separated in larger amount by liquid chromatogra-phy on graphite column.The column was first eluted with a mixture of hexane and toluene,and then withtoluene.The eluates were monitored by UV/visible absorption spectroscopy.Graphite column shows high perfor-mance for separation.and much larger quantities of pure C_(60) can be easily obtained.The synthesis of fullerenes(C_(60) and C_(70))in macroscopic quantities has stimulated scientists to study on themethod for separating C_(60) and C_(70).Because of the poor solubility of fullerenes C_(60)/C_(70) in most organic solvents,theseparation of C_(60) and C_(70) proved to be a challenging task.Most attempts at the separation have used silica and alu-mina as the stationary phase and a mixture of hexane and benzene(or toluene)as the mobile phase.Fullerenes,however,have only limited solubility in hexane,these separations are usually only achieved by limit-ing the amount of sample to a few milligrams.The hexane-silica technique using phenylglycine based HPLCcolumns appears to offer good separation,but only for submilligram amounts. The use of graphite powder as the stationary phase in liquid chromatography is an advanced separation tech-nique for fullerenes C_(60)/C_(70).The technique is based on that the fullerene-C_(60) is different from C_(70) in the de-gree of electron delocalisation,and C_(60) is much less diamagnetic than C_(70).It is expected that the dissimilarity willcause the C_(60)/C_(70) molecules to exhibit different interactions with graphite,and can be separated from each other onthis basis.     

Electrochemical Determination of Alkaline Phosphatase in Human Serum by Differential Pulse Voltammetry

Differential pulse voltammetry(DPV) was applied to the determination of alkaline phosphatase(ALP) activity in human serum with phenyl phosphate as the substrate. Phenyl phosphate can enzymatically be hydrolyzed to produce phenol which is quantified by DPV at 660 mV(vs. Ag/AgCl) in the concentration rangeof 2.0--100 μmol/L. The standard curve for ALP is linear over the range from 0.06 to 1000U/L with a relative standard deviation of 3.0%. The conditions for the enzymatic reaction and voltammetric detection were optimized and the kinetic constants were also examined. The human serum samples were tested by this method and the results were in good agreement with those obtained by the routine p-nitrophenyl phosphate spectrophotometric method.     

A disposable cobalt-based phosphate sensor based on screen printing technology

Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consists of a fully integrated cobalt(Co) electrode, which is a layer of carbon conductive ink(C) physically doped with Co powder, and Ag/AgCl reference electrode. The SEM images show that the morphology of the Co electrode changes after exposure to the phosphate solution, indicating that the expendable reaction exists during the measurement. At the Co/C ratio of 1:99, the cobalt-based phosphate sensor shows phosphate-selective potential response in the range of 10-4 to 10-1 mol/L, yielding a detection limit of 1×10-5 mol/L and a slope of over 30 mV/decade in acidic solution(pH 4.5) for H2PO4-. The proposed screen-printed sensor also exhibited significant reproducibility with a small repeated sensing deviation(i.e., relative standard deviation(R.S.D.) of 0.5%) on a single sensor and a small electrode-to-electrode deviation(i.e., R.S.D. 3.2%). The recovery study of H2PO4- in real wastewater samples gave values from 95.4% to 101.8%, confirming its application potential in the measurement of phosphate in real samples. Apart from its high selectivity, sensitivity, and stability comparable with a conventional bulk Co-wire electrode, the proposed phosphate sensor still yields many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices such as flow injection analysis.     

Extraction of cobalt(Ⅱ) from aqueous solution by N,N'-carbonyl difatty amides

The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal.In this study,solvent extraction of Co(Ⅱ) from aqueous solution using a mixture of N,N’-carbonyl difatty amides(CDFAs) synthesised from palm oil as the extractant was carried out.The effects of various parameters such as acid,contact time,extractant concentration,metal ion concentration and stripping agent and the separation of Co(Ⅱ) from other metal ions such as Fe(Ⅱ),Ni(Ⅱ),Zn(Ⅲ) and Cd(Ⅱ) were investigated.It was found that the extraction of Co(Ⅱ) into the organic phase involved the formation of 1:1 complexes.Co(Ⅱ) was successfully separated from commonly associated metal ions such as Fe(Ⅱ),Ni(Ⅱ),Zn(Ⅲ) and Cd(Ⅱ).Co(Ⅱ) stripping from the loaded organic phase was studied in aqueous solution.These results are useful to recover Co(Ⅱ) from aqueous solution utilising(CDFAs) as an extractant.     

Novel Analogues of a-Terthienyl, Thienyl 1, 3, 4-Thia(oxa)diazoles as Potential Photoactivated Insecticides: Synthesis and Bioactivity

a-Terthienyl (aT) is a phototoxic compound originated from the marigold Tagetes eretra1. The aT and its analogues have been widely used for photodynamic killing of insects, in photodynamic therapy for dermatophytes, and in human immunodeficiency virus (HIV)2. The phototoxicity of aT and its derivatives are attributed to their triplet states that easily generate a reactive oxygen species (ROS). Many of the biomolecules and enzymes are targets of these ROS, such as DNA in vitro and in v…     

STRUCTURE OF (Trp)~(B1)-INSULIN AT 2RESOLUTION

The rhombohedral crystal structure of [Trp]~(B1)-insulin has been refined, using data to 2 and atomic coordinates of 2-zinc porcine insulin as starting model, and through the use of the restrained least-squares method, to an R value of 0.24. The result of refinement shows that in comparison with the 2-zinc insulin structure, some changes in local conformation occur, and are asymmetric for the two independent molecules related by a local two-fold axis. The obvious conformational changes are found to be in molecule 1, at its B-chain N-terminus and A13-residue region.     

Incorporation of layered tin(Ⅳ) phosphate in graphene framework for high performance lithium-sulfur batteries

To anchor the polysulfide and enhance the conversion kinetics of polysulfide to disulfide/sulfide is critical for improving the performance of lithium-sulfur battery.For this purpose,the graphene-supported tin(Ⅳ) phosphate(Sn(HPO_4)_2·H_2 O,SnP) composites(SnP-G) are employed as the novel sulfur hosts in this work.When compared to the graphene-sulfur and carbon-sulfur composites,the SnP-G-sulfur composites exhibit much better cycling performance at 1.0 C over 800 cycles.Meanwhile,the pouch cell fabricated with the SnP-G-sulfur cathodes also exhibits excellent performance with an initial capacity of1266.6 mAh g^-1(S) and capacity retention of 76.9% after 100 cycles at 0.1 C.The adsorption tests,density functional theory(DFT) calculations in combination with physical cha racterizations and electrochemical measurements provide insights into the mechanism of capture-accelerated conversion mechanism of polysulfide at the surface of SnP.DFT calculations indicate that the Li-O bond formed between Li atom(from Li_2 S_n,n=1,2,4,6,8) and O atom(from PO_3-OH in SnP) is the main reason for the strong interactions between Li_2 S_n and SnP.As a result,SnP can effectively restrain the shuttle effect and improving the cycling performance of Li-S cell.In addition,by employing the climbing-image nudged elastic band(ciNEB) methods,the energy barrier for lithium sulfide decomposition(charging reaction) on SnP is proved to decrease significantly compared to that on graphene.It can be concluded that SnP is an effective sulfur hosts acting as dual-functional accelerators for the conversion reactions of polysulfude to sulfide(discharging reaction) as well as polysulfide to sulfur(charging reaction).     

GAS TRANSPORT PROPERTIES OF A POLYIMIDE BASED ON 2, 2-BIS (3, 4-DECARBOXYPHENYL) HEXAFLUOROPROPANE AND meta-PHENYLENEDIAMINE

By means of a vacuum time-lag method, gas transport properties of apolyimide based on 2, 2- bis (3, 4- decarboxyphenyl ) hexafluoropropane dianhydride (6FDA )and meta- phenylenediamine (mPDA ) have been measured as a function of upstream pres-sure and temperature. The results show that no gas-induced plasticization occurs for thispolyimide in the upstream pressure range from 1 atm to 20atm. The temperature depen-dence of P and D can be described by the Arrhenius equations. The activation energiesof permeation and diffusion were obtained for the gas/polymer pair studied and correlatedwith the size of penetrant gas.     

非晶态金属-磷酸铝催化正庚醛和苯甲醛羟醛缩合制茉莉醛(英文)

Amorphous aluminophosphate (AlP) and metal‐aluminophosphates (MAlPs, where M=2.5 mol%Cu, Zn, Cr, Fe, Ce, or Zr) were prepared by coprecipitation method. Their surface properties and catalytic activity for the synthesis of jasminaldehyde through the aldol condensation of n‐heptanal and benzaldehyde were investigated. The nitrogen adsorption‐desorption isotherms showed that the microporosity exhibited by the aluminophosphate was changed to a mesoporous and macroporous structure which depended on the metal incorporated, with a concomitant change in the surface area. Temperature‐programmed desorption of NH3 and CO2 revealed that the materials possessed both acidic and basic sites. The acidic strength of the material was either increased or decreased depending on the nature of the metal. The basicity was increased compared to AlP. All the materials were X‐ray amorphous and powder X‐ray diffraction studies indicated the absence of metal oxide phases. The Fourier transform infrared analysis confirmed the presence of phosphate groups and also the absence of any M‐O moieties in the materials. The selected organic reaction occurred only in the presence of the AlP and MAlPs. The selectivity for the jasminaldehyde product was up to 75%with a yield of 65%. The best conversion of n‐heptanal with a high selectivity to jasminaldehyde was obtained with FeAlP as the catalyst, and this material was characterized to have less weak acid sites and more basic sites.     

STUDY ON THE CHAIN-EXTENDING REACTION OF POLY (ETHYLENE TEREPHTHALATE) WITH 2, 2′-BIS (4H-3, 1-BENZOXAZIN-4-ONE)

2,2'-Bis (4H-3, 1-benzoxazin-4-one) (BBON) has been proved to be an effective chainextender for poly (ethylene terephthalate) (PET). In order to study the reaction mechanismand kinetics of chain-extending reaction, β-bishydroxyethylene terephthalate (BHET) wasselected as model compound. The NMR data, IR spectra and number average molecularweight (M_n) of the products obtained from the reaction of BBON and BHET verify thatBBON is a hydroxyl-reactive extender. The mechanism was discussed. Kinetics dataindicate that extending reaction is a second order reaction, and BBON has high reactivity.The activation energy (E_a) was measured.     

Raising the capacity of lithium vanadium phosphate via anion and cation co-substitution

The pursuit for batteries with high specific energy provokes the research of high-voltage/capacity cathode materials with superior stability and safety as the alternative for lithium iron phosphate.Herein,using the sol-gel method,a lithium vanadium phosphate with higher average discharge voltage(3.8 V,vs.Li+/Li) was obtained from a single source for Mg2+ and Cl-co-substitution and uniform carbon coating,and a nearly theoretical capacity(130.1 mA h g^-1) and outstanding rate performance(25 C) are acquired together with splendid capacity retention(80%) after 650 cycles.This work reveals that the well-sized anion and cation substitution and uniform carbon coating are of both importance to accelerate kinetic performance in the context of nearly undisturbed crystal structure for other analogue materials.It is anticipated that the electrochemistry comprehension will shed light on preparing cathode materials with high energy density in the future.     

[Cu(2,2'-bpy)Cl2]和[Cu(1,10-phen)C12]在多金属氧酸盐上的多相化:选择性氧化四氢化萘的新催化剂

Mononuclear Cu(II)bipyridine(1)and phenantroline complexes(2)were synthesized and immobilized by different procedures on H3PW12O40 polyoxometalate(POM).Characterization by XRD and SEM-EDX were performed to assess the preservation of the Keggin structure and stoichiometry of the complex.The immobilized complexes were tested as heterogeneous catalysts for the partial oxidation of tetralin(1,2,3,4-tetrahydronaphthalene)using hydrogen peroxide as oxidant in acetonitrile/water as solvent.[Cu(2,2’-bpy)Cl][H2PW12O40] and[Cu(1,10-phen)Cl][H2PW12O40]oxidized tetralin at room temperature,with 16%conversion with(2),to 1-tetralone and 2-tetralone with 83%selectivity.However,the selectivity for 1-tetralone was only 56%.Different preparation methods for the heterogenization of these complexes on the POM Keggin unit were compared and used to enhance the selectivity to 1-tetralone to 75%.     

Synergic Extraction of Uranium Thiocyanate by the Ternary System of ABC Species Composed of PMBP-TBP-(C6H5)4AsCI

The synergic extraction of uranyl thiocyanate with binary system of 1-phenyl-3-methy1~4-benzoylpyrazolone-5 (PMBP)and tributyl phosphate(TBP)or tetraphenylarsonium chloride [(C6H5)4AsCl] and ternary system of PMBP-TBP-(C6H5 )4AsCl was studied.There was an obvious synergic effect of uranium (VI)from thiocyanate medium in binary and ternary systems.The formation of a ternary extracted complex,(C6H5)4AsUO2.(NCS)A2 TBP,was confirmed by the slope method.A method was first proposed for the calculation of the equilibrium constant of ternary synergic reaction.     

Synthesis, characterization, antitumor activity of nickel(Ⅱ) and cobalt (Ⅱ) complexes of 2,2''''-diamino-4,4''''-bithiazole and their interaction with dGMP

New complexes,of bis(2,2'-diamino-4,4'-bithiazole)sulfate nickel(Ⅱ) and bis(2,2'-diami-no-4,4'-bithiazole)sulfate cobalt(Ⅱ),have been prepared.The complexes were characterized by infrared and UV-Vis spectroscopy,1H NMR,elemental analyses and molar conductivity.The effect of these complexes on the DNA synthesis of sarcoma 180 cells has been studied by the technique of isotopic liquid scintillation.The results indicated that complexes show ability to inhibit DNA synthesis of the tumor cells.In order to provide a molecular basis for understanding the biological effects,the probe,[trana-en2Os(η2-H2)](CF3SO3)2 (en,ethylenediamine) as a monitor was first used to explore interaction of the complexes with 2'-deoxyguanosine-5'-monophosphate (dGMP).