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351.
Plasma-based technologies are an exciting alternative for cellulose andpaper modification. Barrier coatings and surface functionalization of celluloseenhances properties and creates new possibilities for cellulose-based products.A parallel plate radio frequency (RF)-plasma reactor was used to modify papersubstrates under discharge parameters such as power, time and pressure. Carbontetrafluoride RF-plasma treatment of paper caused intense fluorination and itwas demonstrated that the fluorination reaction mechanisms can be controlled bythe external plasma parameters. Fluorine contents as high as 51.3% (contactangle=147°) were obtained for the treated cellulose. It was shown that eventreatment times as low as 30 s can generate relative surface fluorineatomic concentrations as high as 30%. High resolution ESCA and ATR-FTIRanalysisindicated covalently bound CFx functional groups with CF4treatment. It was found that under certain experimental conditionssuper-hydrophobic paper surfaces are created by combining the high surfacefluorine atomic concentrations with specific plasma-generated surfacetopographies. 相似文献
352.
Latif Kelebekli Yunus Kara Metin Balci Ertan ahin 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o432-o434
In the title compound, C16H20Cl2O8, the bicyclic system contains a central non‐planar cyclohexane ring which is fused to a cyclobutane moiety. The cyclohexane ring has a chair conformation and the whole system adopts a syn conformation. The structure provides information on the stereochemical course of the chlorination, photo‐oxidation and hydroxylation steps of the reaction. 相似文献
353.
Mehmet Emin Sengül Abdullah Menzek Ertan Sahin Mustafa Arik Nurullah Saracoglu 《Tetrahedron》2008,64(30-31):7289-7294
Norcaran-2,3,4,5-tetraoles were synthesized starting from methyl 1,3,5-cycloheptatriene-7-carboxylate in several steps. Norcaradiene endoperoxide is the key component; it was obtained by photooxygenation of methyl 1,3,5-cycloheptatriene-7-carboxylate. The other oxygen functionalities are introduced through epoxide ring opening and OsO4-hydroxylation reactions. 相似文献
354.
355.
Two new heterocyclic monoazo disperse dyes were prepared by diazotizing 2-amino-5-methylthiazole and ethyl-1-(2-aminothiazol-4-yl)acetate
and coupling with 1,2-dimethyl-indole. Characterization of the dyes was carried out by using UV–vis, FTIR, 1H-NMR and MS spectroscopic techniques. The structures of the dyes have been determined by single-crystal X-ray diffraction
method. The maximum absorption peaks (λmax) in the ultraviolet and visible (UV–vis) spectra of the hetarylazoindole dyes have been determined by using the density-functional
(DFT method) and time-dependent density-functional (TD-DFT method) theories. Excellent agreement was found between the calculated
and experimental λmax values. 相似文献
356.
Caglar M Ilican S Caglar Y Sahin Y Yakuphanoglu F Hür D 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(2):621-627
The optical properties of sulfonated polyaniline (SPAN) thin film prepared by electrochemical method have been investigated. Polychromic behavior of SPAN thin film (transparent yellow-green-dark blue) was observed when the cyclic voltammograms were taken between -0.25 V and +1.90 V (vs. Ag/AgCl, sat.) during the growth of polyaniline film. In situ UV-vis spectra of the polymers-indium tin oxide (ITO) glass electrode were taken during the oxidation of the polymers at different applied potentials. The direct band gap values of SPAN thin film changed from 3.771 eV to 3.874 eV with the applied potentials. From in situ UV-vis spectra, the optical constants such as refractive index and dielectric constant of the SPAN thin film were determined. The important changes in absorption edge, refractive index and the dielectric constant were observed due to the applied potentials. The refractive index dispersion curves of the film obey the single-oscillator model and oscillator parameters changed with the applied potentials. The most significant result of the present work is in situ spectroelectrochemical method, which can be used to modify the optical band gaps and constants. 相似文献
357.
Tümer M Aslantaş M Sahin E Deligönül N 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(3):477-481
Crystals of the 3,3'-5,5'-tetra-tert-butyl-4,4'-diphenoquinone (TTBDQ) in the reaction mixture DCM/MeOH (1:1, v/v) were obtained as a result of CC coupling reaction of the sterically hindered phenol (2,6-di-tert-butylphenol, DTBP) using the binuclear Co(II) complexes. The oxidation product (TTBDQ), C(28)H(40)O(2), crystallizes in the space group P1 with one-half molecule in the asymmetric unit and the other half generated by an inversion centre. The diphenoquinone moiety is planar within +/-0.016(3)A. The crystal structure is stabilized by intramolecular C-H...O hydrogen bonds. The spectroscopic and electrochemical properties of the TTBDQ also have been studied. 相似文献
358.
The condensation of electron-hole pairs is studied at zero temperature and in the presence of a weak spin-orbit coupling (SOC) in coupled quantum wells. Under realistic conditions, a perturbative SOC can have observable effects in the order parameter of the condensate. First, the fermion exchange symmetry is absent. As a result, the condensate spin has no definite parity. Additionally, the excitonic SOC breaks the rotational symmetry yielding a complex order parameter in an unconventional way; i.e., the phase pattern of the order parameter is a function of the condensate density. This is manifested through finite off-diagonal components of the static spin susceptibility, suggesting a new experimental method to confirm an excitonic condensate. 相似文献
359.
Diran Herebian Marc Lamshöft Ertan Mayatepek Ute Spiekerkoetter 《Rapid communications in mass spectrometry : RCM》2010,24(6):791-800
The objective of our work was to identify known and unknown metabolites of the drug NTBC (2‐(2‐nitro‐4‐trifluoromethylbenzoyl)‐1,3‐cyclohexanedione) in urine from patients during the treatment of hereditary tyrosinemia type 1 (HT‐1) disease, a severe inborn error of tyrosine metabolism. Two different mass spectrometric techniques, a triple stage quadrupole and an LTQ‐Orbitrap (Fourier transform mass spectrometry (FTMS)), were used for the identification and the structural elucidation of the detected metabolites. Initially, the mass spectrometric (MS) approach consisted of the precursor ion scan detection of the selected product ions, followed by the corresponding collision‐induced dissociation (CID) fragmentation analysis (MS2) for the targeted selected reaction monitoring (SRM) mode. Subsequently, accurate and high‐resolution full scan and MS/MS measurements were performed on the possible metabolites using the LTQ‐Orbitrap. Final confirmation of the identified metabolites was achieved by measuring commercially supplied or laboratory‐synthesized standards. Altogether six metabolites, including NTBC itself, were extracted, detected and identified. In addition, two new NTBC metabolites were unambiguously identified as amino acid conjugates, namely glycine‐NTBC and β‐alanine‐NTBC. These identifications were based on their characteristics of chromatographic retention times, protonated molecular ions, elemental compositions, product ions (using CID and higher‐energy C‐trap dissociation (HCD) techniques) and synthesized references. The applied MS strategy, based on two different MS platforms (LC/MS/MS and FTMS), allowed the rapid identification analysis of the drug metabolites from human extracts and could be used for pharmaceutical research and drug development. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
360.