Photoassisted reaction of chemical warfare agent VX droplets under UV light irradiation

A photoassisted reaction of O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) droplets in air was carried out. The experimental results indicated that VX droplets could be easily and chemically transformed into other compounds under irradiation of a germicidal lamp over sufficient time. Quantum chemical calculation results demonstrated that UV light less than 278 nm wavelength could possibly initiate photoreaction of VX and that both P-S and P=O bonds in the VX molecule were lengthened. The identification of reaction products by gas and liquid chromatography mass spectroscopy and NMR revealed that the VX molecule in air under UV light irradiation could undergo isomerization of S-esters to O-esters, cleavage of P-S, S-C, and C-N bonds, and ozonation of tertiary amines.     

Copper corrosion in buffered and non-buffered synthetic seawater: a comparative study

The electrochemical behaviour of copper in neutral buffered and non-buffered synthetic seawater and in pure chloride solutions has been studied by cyclic voltammetry, weight loss measurements, open circuit potential and scanning electron microscopy (SEM). Values of the repassivation potentials of Cu in non-buffered and buffered synthetic seawater, at 50 mV s^–1, were 0.12 and 0.46 V vs. SCE, respectively. The sharpness, heights and location of the different peaks as well as their charges were shown to be influenced by the composition of the solution, buffering conditions, deoxygenation, polarization potential and time. High chloride concentrations lead to higher oxidation charges. The anodic and the cathodic charges were shown to increase as the chloride concentration increases. The open circuit potential transients of copper in non-deoxygenated, non-buffered synthetic seawater indicate pitting from the beginning of the exposure, while in buffered solutions the pitting appeared only after a quite long exposure period, i.e. after 40 days. Corrosion rates of Cu samples after 3 months of immersion were higher in solutions of pure chloride (0.5 M) than in synthetic seawater. After six months the differences were even more noticeable. SEM images have showed a somewhat higher density of pits on copper samples immersed in the chloride solution (0.5 M), in comparison with those in synthetic seawater.     

高效前沿分析的发展及在药物-蛋白结合研究中的应用

介绍了高效前沿分析方法的原理、特点、种类，综述了它在药物与蛋白结合研究中的应用及国内外研究概况；通过与高效液相色谱／前沿分析比较，阐明了毛细管电泳／前沿分析在药物蛋白结合研究中的优势；分析了在药物与蛋白结合研究中所采用的各种研究方法，通过与这些研究方法的比较，阐明了高效前沿分析的优越性及其广阔的应用前景，同时提出了在高效前沿分析方法中有待完善和注意的问题。     

Solid-phase reagent for molecular spectroscopic determination of heavy metal speciation in natural water

A solid-phase reagent based on 1-(4-adamantyl-2-thiasolylazo)-2-naphthol adsorbed onto silica gel was prepared for Co(II) recovery and preconcentration prior to its sorption-spectroscopic detection. The immobilized reagent was applied to the determination of free cobalt ions in natural water. The solid-phase reagent and chemiluminescent method coupled with membrane filtration, gel-permeation and ion-exchange chromatography were applied to the study of the speciation of iron and cobalt in water from the Dnieper reservoirs and lakes of Kyiv City; their predominant forms were complexes of Fe(III) and Co(II) with dissolved organic matter and fulvic acids play a main role in their complexation.     

IR study of heterogeneity of OH groups in zeolite HY-splitting of OH and OD bands

We have been studying the problem of heterogeneity of OH groups in zeolites HY for a long time. The heterogeneity was suggested by the shift of the IR band of OH groups restoring upon ammonia desorption and also by the fact that the band of OH groups forming hydrogen bonds was relatively broad (broader than for homogeneous acidic OH). In the present study we present another important argument for heterogeneity: the splitting of the IR band of free OH and OD groups in a zeolite of Si/Al=8.3 dealuminated by (NH₄)₂SiF₆ treatment. Such a splitting is the best seen in low temperature spectra of OD groups. We found less acidic 3640 cm⁻¹ (AlO)(SiO)₂SiO₁HAl(OSi)₃ and more acidic 3625 cm⁻¹ (SiO)₃SiO₁HAl(OSi)₃ groups. The presence of these two kinds of hydroxyls corresponds to the presence of Si(2Al) and Si(1Al), respectively, detected in ²⁹Si MAS NMR spectra. We also found a small amount of strongly acidic 3599 cm⁻¹ hydroxyls interacting with extraframework Al species.     

燃烧催化剂中LaAlO3作为第2载体的研究

在载体堇青石表面涂覆一层LaAlO3作为第二载体，用浸渍法制备负载型LaMnO3、LaCoO3等钙钛矿型燃烧催化剂时，发现能促进LaMnO3等活性相的生长，从而提高了二甲苯完全氧化的催化活性；对于负载型LaCo3O3催化剂，可避免因用γ－Al2O35作第二载体而生成的低活性CoAl2O4类尖晶石相，因而有利于提高催化剂的耐热性。     

Molecular recognition properties of salicylic acid-imprinted polymers

Summary Two molecularly imprinted polymers (MIP) have been prepared using the acidic drug salicylic acid, which can form intramolecular hydrogen bond, as the template and acrylamide or 4-vinylpyridine as the functional monomer. HPLC was used to evaluate the binding performance of the MIP for the template and for several analogues. The results showed that the MIP (P₂) prepared using acrylamide as the functional monomer had no molecular imprinting effect whereas that (P₁) prepared using 4-vinylpyridine as the functional monomer had a significant molecular imprinting effect. The reason the molecular imprinting effect was different for the two MIP was elucidated and the molecular recognition properties of P₁ were studied in detail. It was confirmed that electrostatic interaction played an important role in the molecular recognition of P₁. Scatchard analysis showed that two types of binding site with distinctly different affinity were formed in P₁. Their dissociation constants were estimated to be 7.6×10⁻⁵ mol L⁻¹ and 3.2×10⁻³ mol L⁻¹, respectively. Because P₁ has high affinity and selectivity for salicylic acid not only in organic systems but also in water-containing systems, it gives P₁ the potential for use in the enrichment, separation, and detection of salicylic acid in biological fluids.     

氯化二氯代四苯基卟啉磷合二氯甲烷的晶体结构

氯化二氯代四苯基叶啉磷（Dichloro（5，10，15，20－tetraphenylporphinato）－phosphorus（V）chloride，［PCl2TPP］Cl）是典型的非金属卟琳配合物．据文献报导［1］该配合物能够与噻吩类化合物反应，所得单体经电解氧化，可生成具有导电性的聚合物．因此，测定［PCl2TPP］Cl的分子结构有着十分重要的意义．1标题化合物的制备及单晶生长标题化合物技文献［2］合成．用于X－射线衍射的单晶样品是将标题化合物的二氯甲烷／正庚烷混合溶液静置数周后得到的．单晶为紫色，用于X－射线衍射测定的晶粒尺寸为0．38mm×0．38mm×0．28mm．…     

时间分辨脉冲光声量热法及其应用

光声量热法是一种研究快速光化学反应的新方法，已广泛应用于有机和有机金属化学中涉及自由基中间体以及生物体系中光诱导化学反应生成亚稳态物质的动力学和热力学性质的研究。本文介绍了光声量热的基本原理、实验装置和它在化学、生物体系中的应用。