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991.
A new group of imidazolium salt-based chiral ionic liquids have been prepared and characterized. The chiral ionic liquids obtained are stable in air, in contact with water and popular organic solvents. Their physicochemical properties, single-crystal X-ray structures, antimicrobial activities, and antielectrostatic effects have been determined. The chiral ionic liquids synthesized have proven to represent not only potential new solvents in asymmetric synthesis but also effective disinfectants with antielectrostatic activity. 相似文献
992.
2,6-diacetylpyridinediphenylhydrazone perchlorate was prepared and characterized by spectroscopic (IR, ESI–MS, UV–Vis, 1H NMR) and analytical data and its crystal structure was determined by single X-ray analysis. The lanthanum(III), praseodymium(III),
and neodymium(III) perchlorate complexes of 2,6-diacetylpyridinediphenylhydrazone were prepared in a direct reaction of the
ligand with appropriate metal perchlorates. The spectroscopic and analytical data indicate 1:2 metal to ligand stoichiometry.
In all the complexes the hydrazones act as monodeprotonated terdentate NNN donor chelators. The same lanthanum(III) complex
was also obtained in a one-step condensation reaction between 2,6-diacetylpyridine and phenylhydrazine in the presence of
lanthanum(III) perchlorate. 相似文献
993.
Vinita Dubey Sanila Velikeloth Maciej Sliwakowski Gary Mallard 《Accreditation and quality assurance》2009,14(8-9):431-437
The Organisation for the Prohibition of Chemical Weapons (OPCW) has been organising and conducting Official Proficiency Tests (PT) since 1996 in accordance with ILAC-G13 to certify laboratories for the analysis of authentic samples under the provision of Chemical Weapons Convention. The tests are part of a mechanism to ensure that there are laboratories that have proven competence in the analysis of chemicals related to the Convention. Laboratories that have successfully completed the tests are designated by the Director General of the OPCW for analysis of authentic samples. To maintain the Designated Laboratory status, a laboratory must take and pass at least one of the two proficiency tests offered per calendar year. Unlike many proficiency tests, the OPCW PT is qualitative, that is the laboratories must determine if any of a very large set (essentially infinite) of chemicals relevant to the Convention are present in the samples. The tests are organised with the assistance of two laboratories, one preparing the test samples, and the other evaluating the test results. The paper provides an overview of the current status of these PTs and outlines salient features regarding procedure and scope of tests, selection of assisting laboratories, scoring and performance rating of participating labs. The emerging issues are also briefly discussed. 相似文献
994.
A certain invariant Hamiltonian arising from the standard membrane matrix model via conjugating any of the supercharges by a cubic,
octonionic, exponential is proven to have a spectrum covering the whole half-axis . The model could be useful in determining a normalizable zero-energy state in the original SO(9) invariant SU(N) matrix model.
Submitted: November 5, 2008.; Accepted: January 19, 2009. 相似文献
995.
Maciej Jabłoński 《Journal of Thermal Analysis and Calorimetry》2009,96(3):971-977
The knowledge about kinetics of the reaction titanium raw materials with sulphuric acid is very important from the reason
of influence of initial conditions of reaction on efficiency, quality and safety. One of the very important parameter, which
influence on kinetics of this reaction is distribution of particles sizes of raw material. Presented results of investigation
of reaction thermokinetics of ilmenite with different particles sizes, obtained in special construction of calorimeter, demonstrated
very great influence of this parameter on rate of reaction with sulphuric acid. On the base of experimental investigation
the kinetic model of this reaction was elaborated which takes into account density of particles sizes distribution described
by the function of Rosin–Rammler. Presented model was tested on the base of experimental data of ilmenite with sulphuric acid
reaction. 相似文献
996.
Leszek Lapinski Maciej J. Nowak Jacek Nowacki Michat F. Rode Andrzej L. Sobolewski Prof. 《Chemphyschem》2009,10(13):2290-2295
The occurrence of photoinduced hydrogen atom transfer between two remote spots of a molecule is experimentally demonstrated. This photoprocess involves the intermediacy of an intramolecular “crane”. In an experimental case study, 7‐hydroxy‐4‐methylquinoline‐8‐carbaldehyde monomers isolated in low‐temperature Ar matrices are investigated. On UV (λ>295 nm) irradiation, a hydrogen atom is transferred from the O7H group to the N1 atom of the quinoline ring. Subsequent irradiation with UV (λ>360 nm) light reveals that the phototransformation is partially photoreversible. In the studied hydrogen‐atom‐transfer process, the exocyclic carbaldehyde group plays the role of an intramolecular crane. The possible application of systems analogous to 7‐hydroxy‐4‐methylquinoline‐8‐carbaldehyde as optically driven molecular switches is discussed. 相似文献
997.
Zbigniew Florjańczyk Maciej Dębowski Andrzej Plichta Aleksandra Ćwil Marcin Affek Elżbieta Chwojnowska Anna Kania 《Macromolecular Symposia》2011,308(1):77-86
Summary: The possibility of applying basic aluminum carboxylates as the cross-linking monomers in radical polymerization processes as well as the initiators for ATRP of styrene and coordination ROP of heterocyclic monomers was examined. It was established, that aluminum carboxylates containing in their structure the acrylic and lauric acids derivatives show high activity in the copolymerization with vinyl monomers which results in the hybrid polymer networks formation. In the typical ATRP conditions, polymers grafted with styrene are obtained while basic aluminum 2-bromopropionate is used as the initiator. Hybrid composites i.e. core-shell nanospheres can be obtained in this way at low degree of polymerization. Nanoparticles of basic aluminum caroboxylates when reacted with triethylaluminum show high activity as initiators in the polymerization processes of ε-caprolactone, trimethylene carbonate as well as propylene and ethylene oxides. Cross-linked products in the form of a gel were formed as the result of ROP in such systems. However, linear polymers characterized by Mn above 104 and PDI ≥ 1.9 were obtained after aluminum residuals removal. 相似文献
998.
In this study we attempt to explain the molecular aspects of amino acids' hydration. Glycine and its N-methylated derivatives: N-methylglycine, N,N-dimethylglycine, and N,N,N-trimethylglycine were used as model solutes in aqueous solution, applying FT-IR spectroscopy as the experimental method. The quantitative version of the difference spectra method enabled us to obtain the solute-affected HDO spectra as probes of influenced water. The spectral results were confronted with density functional theory calculated structures of small hydration complexes of the solutes using the polarizable continuum model. It appears that the hydration of amino acids in the zwitterionic form can be understood allowing a synchronized fluctuation of hydrogen bonding between the solute and the water molecules. This effect is caused by a noncooperative interaction of water molecules with electrophilic groups of amino acid and by intramolecular hydrogen bond, allowing proton transfer from the carboxylic to the amine group, accomplishing by the chain of two to four water molecules. As a result, an instantaneous water-induced asymmetry of the carboxylate and the amino group of amino acid molecule is observed and recorded as HDO band splitting. Water molecules interacting with the carboxylate group give component bands at 2543 ± 11 and 2467 ± 15 cm(-1), whereas water molecules interacting with protons of the amine group give rise to the bands at 2611 ± 15 and 2413 ± 12 cm(-1). These hydration effects have not been recognized before and there are reasons to expect their validity for other amino acids. 相似文献
999.
Urszula Domańska Maciej Zawadzki Magdalena Zwolińska 《The Journal of chemical thermodynamics》2011,43(5):775-781
The new quinolinium ionic liquid has been synthesised as a continuation of our work with quinolinium-based ionic liquids (ILs). The work includes specific basic characterisation of synthesized compounds: N-hexylquinolinium bromide, [HQuin][Br] and N-hexylquinolinium bis{(trifluoromethyl)sulfonyl}imide [HQuin][NTf2] by NMR spectra, elementary analysis and water content. The basic thermal properties of the pure [HQuin][NTf2] i.e. melting and glass-transition temperatures, the enthalpy of fusion as well as heat capacity have been measured using a differential scanning microcalorimetry technique (DSC) and thermal analysis instrument (TA). Densities and viscosities were determined as a function of temperature. Phase equilibria for the binary systems: {[HQuin][NTf2]) + aromatic hydrocarbon (benzene, or toluene, or ethylbenzene, or n-propylbenzene), or an alcohol (1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol)} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (270 to 320) K. For all the binary systems with benzene and alkylbenzenes, the eutectic diagrams were observed with immiscibility gap in the liquid phase beginning from (0.13 to 0.28) mole fraction of the IL with very high an upper critical solution temperature (UCST). For mixtures with alcohols, the complete miscibility was observed for 1-butanol and immiscibility with UCST in the liquid phase for the remaining alcohols. The typical dependence was observed, that with increasing chain length of an alcohol the solubility decreases. The well-known NRTL equation was used to correlate experimental (solid + liquid), SLE and (liquid + liquid), LLE phase equilibria data sets. For the systems containing immiscibility gaps, (IL + an alcohol) parameters of the LLE correlation were used to the prediction of SLE. 相似文献
1000.
Maciej A. Hodorowicz Agata Piaskowska Katarzyna M. Stadnicka 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(7):m173-m176
catena‐Poly[benzyldecyldimethylammonium [plumbate(II)‐tri‐μ‐bromido]], {(C19H34N)[PbBr3]}n, crystallizes as an inorganic–organic hybrid following monoclinic space‐group symmetry P21/c. The structure consists of extended chains running along the [001] direction and built of [PbBr3]− units. These inorganic chains are separated by interdigitated ammonium cations which form hydrophilic layers through weak C—H...Br interactions. The architecture is essentialy the same as found for n‐alkylbenzyldimethylammonium bromides. 相似文献