Synthesis and Crystal Structure of a New Zn(II) Nitronyl Nitroxide Complex [Zn(NIT4Py)(PDA)(H_2O)_3]

1 INTRODUCTION Nitronyl nitroxides, independently or in combina- tion with metal ions, have been one of the most wi- dely studied systems in molecular magnetism for understanding radical-radical or metal-radical inte- ractions as well as for synthesizing organic ferroma- gnets and metal-radical magnetic materials[1～4]. Up to now, lots of metal-radical complexes have been reported[5～8]. On the other hand, cooperative inter- molecular interactions, such as coordination bonds, hydrogen bon…     

Synthesis and Crystal Structure of a 1-D Coordination Polymer {[Cu(NIT4py)_2(ip)]·6H_2O}_n

1 INTRODUCTION Pyridyl-substituted nitroxide radicals have at- tracted considerable attention in recent years due to the ability to coordinate with metal ions and act as magnetic couplers, giving rise to new functional ma- terials with particular magnetic and optical prope- rties as well as a variety of structural topologies[1~3]. Considerable efforts have been made in designing and preparing multi-dimensional materials with app- ropriate bridges, such as pseudohalide, dicyanide, dicyanoa…     

Analysis of tensides in complex samples with comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

Multidimensional gas-chromatographical analysis of various tensides of natural or synthetic origin in cosmetic products is demonstrated. Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry allows the qualitative and quantitative determination of alkyl polyglucosides (AG), fatty alcohol ethoxylates (FAEO), fatty alcohol sulfates (FAS), fatty alcohol ether sulfates (FAES) and cocamidopropyl betaines (CAPB) in shower gel and cleaning agents. The samples were aliquoted in two parts. The first part was silylated, diluted and analysed; then, in order to detect anionic tensides (FAES, FAS) too, the second aliquot was hydrolysed before being silylated for analysis. Because of their amphoteric character, the betaines can only be analysed by gas chromatography after thermal decomposition in the injector, which leads to the corresponding amidoamines among other products.     

Synthesis and Crystal Structure of Ethyl 5-Amino-1-[（5′-methyl-1′- t-butyl-4′-pyrazolyl）carbonyl]-3-methylthio-1H-pyrazole-4-carboxylate

1INTRODUCTIONPolarizedketenedithioacetalshavebeenex-tensivelyusedasbuildingblocksinorganicsyn-thesis,especiallyinthesynthesisofheterocycliccompounds[1～6].Pyrazoleanditsderivativesrepre-sentoneofthemostactiveclassesofcompoundspossessingwidespectraofbiologicalactivities.Overthepastfewyears,considerableevidenceshavebeenaccumulatedtodemonstratetheefficacyofpyrazolederivatives,suchasantibacterial[7],fun-gicidal[8],herbicidal[9],insecticidal[10]andotherbiologicalactivities[11,12].Uptonow,alarg…     

Formation and Structure of [Al_(13)(μ_3-OH)_6(μ_2-OH)_6(μ_2-OH)_(12)(H_2O)_(24)]Cl_(15)·13H_2O

1 INTRODUCTION At present, the polyaluminium compounds are mainly studied by single-crystal X-ray diffraction method to obtain the components, structures and exis- tence forms of aluminium in hydrolysis system, and then hydrolysis courses and mechanisms of each hydrolytic polyaluminium cation could be further dis- closed[1～5]. Generally, the single crystals suitable for X-ray diffraction are obtained from the crystallization of polyaluminium cations into sulfates or selenates. Following …     

Kinetics and mechanism of the reactions of CH3CO and CH3C(O)CH2 radicals with O2. Low-pressure discharge flow experiments and quantum chemical computations

The reactions CH(3)CO + O(2)--> products (1), CH(3)CO + O(2)--> OH +other products (1b) and CH(3)C(O)CH(2) + O(2)--> products (2) have been studied in isothermal discharge flow reactors with laser induced fluorescence monitoring of OH and CH(3)C(O)CH(2) radicals. The experiments have been performed at overall pressures between 1.33 and 10.91 mbar of helium and 298 +/- 1 K reaction temperature. OH formation has been found to be the dominant reaction channel for CH(3)CO + O(2): the branching ratio, Gamma(1b) = k(1b)/k(1), is close to unity at around 1 mbar, but decreases rapidly with increasing pressure. The rate constant of the overall reaction, k(2), has been found to be pressure dependent: the fall-off behaviour has been analysed in comparison with reported data. Electronic structure calculations have confirmed that at room temperature the reaction of CH(3)C(O)CH(2) with O(2) is essentially a recombination-type process. At high temperatures, the further reactions of the acetonyl-peroxyl adduct may yield OH radicals, but the most probable channel seems to be the O(2)-catalysed keto-enol transformation of acetonyl. Implications of the results for atmospheric modelling studies have been discussed.     

Spectrometric study ofα-methylene aromatic araminenone and aminoketone

Thirteenα-methylene aromatic araminenone and fourα-methylene aromatic aminoketones were prepared by modified Mannich reaction.On the basis of isotopic labeling,a plausible way of cleavage was proposed for the formation of the M~ -17 fragment peak in the MS of theα-methylene aromatic araminenone and aminoketones.The characteristic chemical shift of the olefinic protons in ~1H NMR is also discussed.     

Hydrothermal Synthesis and Crystal Structure of Iron Molybdophosphate Fe[Mo_6O_(12)(OH)_3(H_2PO_4)(HPO_4)_2(PO_4)]_2- [Fe(2,2′-bipy)(H_2O)_2]_2[Fe(2,2′-bipy)_3]_2·6H_2O

1 INTRODUCTION Organic-inorganic hybrid materials and polyoxo-metalates have received much attention because of their intriguing structural diversity and potential applications in molecular adsorption, ion exchange, heterogeneous catalysis and nanotech nology as well as in electrical, magnetic and photochemical areas[1, 2]. One of the important ad- vances in the design of new organic-inorganic hybrid materials is utilizing poly- oxometalates’ coordination ability to produce poly- oxoanio…     

Nonionic fluorinated-hydrogenated surfactants for the design of mesoporous silica materials

We have investigated the influence of the ratio between the volume of the hydrophilic head ( V A) and the volume of the hydrophobic part ( V B) of the surfactant on the mesopore ordering. To understand the difference of behavior we have performed a complete study dealing with fluorinated [R m (F)(EO) n ] and hydrogenated [R m (H)(EO) n ] surfactants. Their mixtures have also been taken into account. Here only the phase diagrams and the structural parameters of the liquid crystal phases of the mixed systems are reported. We have shown that the mutual or partial miscibility of the fluorinated and the hydrogenated surfactants depends on the number of oxyethylene units of each surfactant. To follow, various systems were used for the preparation of silica mesoporous materials via a cooperative templating mechanism (CTM). Results clearly reveal that V A/ V B ratios in the range between 0.95 and 1.78 lead to the formation of well-ordered mesostructures. Wormhole-like structures are obtained for higher or lower values. Moreover, results show that from the V A/ V B point of view, polyoxyethylene fluoroalkyl ether surfactants behave like their hydrogenated analogues.     

The electronic structure and adsorption geometry of L-histidine on Cu(110)

The adsorption of L-histidine on clean and oxygen-covered Cu(110) surfaces has been studied by soft X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The valence band spectra, carbon, nitrogen and oxygen 1 s XPS and N K edge absorption spectra were measured for submonolayer, monolayer, and multilayer films. The spectra provide a detailed picture of the electronic structure and adsorption geometry at each coverage. In the monolayer, the histidine molecules are randomly oriented, in contrast to the submonolayer regime, where the molecules are coordinated to the copper surface with the imidazole functional group nearly parallel to, and strongly interacting with, the surface. The pi*/sigma* intensity ratio in NEXAFS spectra at the nitrogen edge varies strongly with angle, showing the imidazole ring is oriented. Adsorption models are proposed.