Synthesis and characterization of fluorine‐containing PAA‐b‐PTPFCBPMA amphiphilic block copolymer

A series of perfluorocyclobutyl (PFCB) aryl ether‐based amphiphilic diblock copolymers containing hydrophilic poly(acrylic acid) (PAA) and fluorophilic poly(p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate) segments were synthesized via successive atom transfer radical polymerization (ATRP). 2‐MBP‐initiated and CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine‐catalyzed ATRP homopolymerization of the PFCB‐containing methacrylate monomer, p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate, can be performed in a controlled mode as confirmed by the fact that the number‐average molecular weights (M_n) increased linearly with the conversions of the monomer while the polydispersity indices kept below 1.38. The block copolymers with narrow molecular weight distributions (M_w/M_n ≤ 1.36) were synthesized by ATRP using Br‐end‐functionalized poly(tert‐butyl acrylate) (PtBA) as macroinitiator followed by the acidolysis of hydrophobic PtBA block into hydrophilic PAA segment. The critical micelle concentrations of the amphiphilic diblock copolymers in different surroundings were determined by fluorescence spectroscopy using N‐phenyl‐1‐naphthylamine as probe. The morphology and size of the micelles were investigated by transmission electron microscopy and dynamic laser light scattering, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Formation and Characterization of Zr<Superscript>4+</Superscript> Stabilized by Neutral Tridentate Ligands in the Gas Phase

Ligated tetrapositive metal ions are rare gas-phase species which tend to form complexes with lower charges due to the high 4th ionization energies of metals. We report the observation of tetrapositive Zr(TMPDA)₃⁴⁺ and Zr(TMOGA)₃⁴⁺ complexes in the gas phase by electrospray ionization of Zr(ClO₄)₄/TMPDA and Zr(ClO₄)₄/TMOGA mixtures. The Zr⁴⁺ center in both complexes is coordinated by nine atoms from three neutral diamide ligands forming nine-coordinate twisted tricapped trigonal prismatic geometry on the basis of DFT calculations. Collision-induced dissociation of both complexes resulted in the loss of protonated ligands to form tripositive Zr(TMPDA)(TMPDA-H)³⁺ and Zr(TMOGA)(TMOGA-H)³⁺ products which retain the IV oxidation state of zirconium at the cost of charge reduction from 4+ to 3+ of the whole complexes. The very high 4th ionization energy of zirconium (34.34 eV) makes tetrapositive zirconium complex the most challenging tetracation to be stabilized against charge reduction in the gas phase to date.

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Preparation and adsorption performance of a NiO/MgF2 composite adsorbent

Fluoride adsorbents have been applied for the purification of UF₆ product from fluorination process. A MgF₂-based adsorbent, NiO/MgF₂, was prepared using NiF₂ as doping agent. The specific surface area of NiO/MgF₂ was 5 times larger than that of MgF₂, its porosity was also larger than that of MgF₂. The saturated adsorption capacity of NiO/MgF₂ for MoF₆ was 21.4?±?1.9 mg g^?1. The desorption behavior was examined by thermogravimetric analysis (TG). The NiO/MgF₂ with adsorbed MoF₆ was investigated using extended X-ray absorption fine structure spectroscopy (EXAFS), which showed no bonding interactions between NiO and MoF₆, while the adsorption of MoF₆ on NiO/MgF₂ was chemisorption via a Mo–F–Mg bond.

     

固态多环芳烃化合物的THz时域光谱研究

利用太赫兹时域光谱技术室温下对芳烃化合物萘、联苯、葸、α-萘酚和β-萘酚在3-73cm^-1(0．1．2．2THz)频谱范围内进行了光谱测量。结果表明，多环芳烃化合物在此波段有不同的吸收特征。不能形成氢键的萘、联苯和蒽在67cm^-1(2．0THz)附近均有一吸收峰，这可能是由于分子之间的振动即晶格振动所引起的；而能够形成氢键的口一萘酚和卢．萘酚，其吸收峰可归结于分子间氢键的相互作用所引起的集体振动模式。1Hz时域光谱不仅能够鉴别分子结构存在微小差别的化合物而且还能鉴别同分异构体。     

Perfluorocyclobutyl-based methacrylate monomers: Synthesis and radical polymerization

A new class of methacrylate monomers containing perfluorocyclobutyl unit was synthesized in multi-steps including crossing-dimerization, demethylation and esterification using commercially available p-substituted phenol, tetrafluoroethylene and methacryloyl chloride as starting materials. These monomers can be polymerized in solution to provide perfluorocyclobutyl-based polymethacrylate, a kind of potential transparent material.     

Radiolabeling of 1-[N',N'-bis(2-chloroethyl)-4-aminophenyl]-N-methyl-fullereno-C60-[1,9-c]pyrrolidine with 125I

Summary A procedure for labeling of a fullerene derivative 1-[N',N'-bis(2-chloroethyl)-4-aminophenyl]-N-methyl-fullereno-C₆₀-[1,9-c]pyrrolidine (C₆₀-C₁₃H₁₈N₂Cl₂) with ¹²⁵I is reported. The compound was first iodinated with a large excess of iodine monochloride and then radiolabeled by isotopic exchange with Na¹²⁵I in a toluene-water two-phase system. The dependence of the radiolabeling yield on the reaction temperature and exchange time was examined. The radiolabeling yield of the compound was as high as 94% after heating for 2 hours at 130 °C.     

蒽醌及其衍生物的THz时域光谱研究

利用太赫兹(terahertz,THz)时域光谱技术室温下进行了蒽醌及其衍生物2_甲基蒽醌、蒽醌_2_磺酸钠、蒽醌_2,6_二磺酸钠、蒽醌_2,7_二磺酸钠在10～55cm-1(0.3～1.65THz)频谱范围内的光谱测量。结果表明,蒽醌及其衍生物在此波段有不同的吸收特征,它们的吸收可能是由于晶格振动引起的。THz时域光谱不仅能够鉴别分子结构存在微小差别的化合物而且还能鉴别同分异构体。     

Radioiodination of C60 Derivative C60(OH)xOy

In this paper water-soluble fullerene derivative C₆₀(OH)_xO_y was radioiodinated with the iodogen method. The labeling yield was determined by radio-TLC. The effects of pH value, reaction time, temperature and amount of the iodogen on the labeling yield were studied. The labeled product was purified by Sephadex G-25 column chromatography and then the stability of ¹²⁵I-C₆₀(OH)_xO_y was examined . The results showed that the radiochemical purity of ¹²⁵I-C₆₀(OH)_xO_y solution with benzylalcohol remained 82.7% after 43 hours.     

放射性碘标记海洛因的初步研究

本文用氯胺－5氧化法对海洛因进行碘－125标记。初步研究了反应PH,同时、温度和海洛因的量对标记率的影响。采用SephadexG-10柱将碘标海洛因与游离碘－125分离,并对试验中出现的现象和可能的反应机理作了初步探讨,产物在SephadexG-10柱上分离纯化后,研究了^125I-heroin的稳定性,结果指出,标记产物在室温放置116h后放化纯度仍达70％。     

The oxidation of UF4 in FLiNaK melt and its electrolysis

Journal of Radioanalytical and Nuclear Chemistry - The oxidation of UF4 in LiF–NaF–KF (FLiNaK) melt with oxygen sparging was conducted at 823&nbsp;K and analyzed by in situ infrared...