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141.
For the determination of vanadium in biological materials by flame AAS an enrichment is described which comprises chelation with oxine and adsorption on activated carbon: The relative standard deviation for 10 g V/L was found to be 6% (n=15).Dedicated to Professor Dr. Dieter Klockow on the occasion of his 60th birthday 相似文献
142.
Bahri Ülküseven Tülay Bal-Demirci Mehmet Akkurt erife Pnar Yaln Orhan Büyükgüngr 《Polyhedron》2008,27(18):3646-3652
The reactions of 5-R-2-hydroxybenzaldehyde-4-allyl-thiosemicarbazone {R: H (L1); Br (L2)} with [MII(PPh3)nCl2] (M = Ni, n = 2 and M = Ru, n = 3) in a 1:1 molar ratio have given stable solid complexes corresponding to the general formula [Ni(L)(PPh3)] and [Ru(HL)2(PPh3)2]. While the 1:1 nickel complexes are formed from an ONS donor set of the thiosemicarbazone and the P atom of triphenylphosphine in a square planar structure, the 1:2 ruthenium complexes consist of a couple from each of N, S and P donor atoms in a distorted octahedral geometry. These mixed-ligand complexes have been characterized by elemental analysis, IR, UV–Vis, APCI-MS, 1H and 31P NMR spectroscopies. The structures of [Ni(L2)(PPh3)] (II) and [Ru(L1H)2(PPh3)2] (III) were determined by single crystal X-ray diffraction. 相似文献
143.
Ülkü Yılmaz Hasan Küçükbay Nihat Şireci Mehmet Akkurt Selami Günal Rıza Durmaz M. Nawaz Tahir 《应用有机金属化学》2011,25(5):366-373
A mixture of benzimidazole salts (2–7), Pd(OAc)2 and K2CO3 in DMF–H2O catalyzes the Suzuki–Miyaura cross‐coupling reactions promoted by microwave irradiation resulting in high yield within a short time. In particular, the yield of the Suzuki–Miyaura reactions with aryl bromides was found to be nearly quantitative. The synthesized benzimidazole salts (2–7) were identified by 1H‐13C, NMR, IR spectroscopic methods and microanalysis. The molecular structure of 1 was determined by X‐ray crystallography. The antibacterial and antifungal activities of the novel benzimidazole derivatives (1–7) were also tested against standard strains. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
144.
Mehmet Atilla Tasdelen Selim Beyazit Deniz Gunes Niyazi Bicak Pinar Tatar A. Levent Demirel Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2011,49(18):4021-4026
The synthesis of poly(p‐phenylene methylene) (PPM)‐based block copolymers such as poly(p‐phenylene methylene)‐b‐poly(ε‐caprolactone) and poly(p‐phenylene methylene)‐b‐polytetrahydrofuran by mechanistic transformation was described. First, precursor PPM was synthesized by acid‐catalyzed polymerization of tribenzylborate at 16 °C. Then, this polymer was used as macroinitiators in either ring‐opening polymerization of ε‐caprolactone or cationic ring‐opening polymerization of tetrahydrofuran to yield respective block copolymers. The structures of the prepolymer and block copolymers were characterized by GPC and 1H NMR investigations. The composition of block copolymers as determined by 1H NMR and TGA analysis was found to be in very good agreement. The thermal behavior and surface morphology of the copolymers were also investigated, respectively, by differential scanning calorimetry and atomic force microscopy measurements, and the contribution of the major soft segment has been observed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
145.
The formation of nanometer‐sized gaps between silver nanoparticles is critically important for optimal enhancement in surface‐enhanced Raman scattering (SERS). A simple approach is developed to generate nanometer‐sized cavities in a silver nanoparticle thin film for use as a SERS substrate with extremely high enhancement. In this method, a submicroliter volume of concentrated silver colloidal suspension stabilized with cetyltrimethylammonium bromide (CTAB) is spotted on hydrophobic glass surfaces prepared by the exposure of the glass to dichloromethysilane vapors. The use of a hydrophobic surface helps the formation of a more uniform silver nanoparticle thin film, and CTAB acts as a molecular spacer to keep the silver nanoparticles at a distance. A series of CTAB concentrations is investigated to optimize the interparticle distance and aggregation status. The silver nanoparticle thin films prepared on regular and hydrophobic surfaces are compared. Rhodamine 6G is used as a probe to characterize the thin films as SERS substrates. SERS enhancement without the contribution of the resonance of the thin film prepared on the hydrophobic surface is calculated as 2×107 for rhodamine 6G, which is about one order of magnitude greater than that of the silver nanoparticle aggregates prepared with CTAB on regular glass surfaces and two orders of magnitude greater than that of the silver nanoparticle aggregates prepared without CTAB on regular glass surfaces. A hydrophobic surface and the presence of CTAB have an increased effect on the charge‐transfer component of the SERS enhancement mechanism. The limit of detection for rhodamine 6G is estimated as 1.0×10?8 M . Scanning electron microscopy and atomic force microscopy are used for the characterization of the prepared substrate. 相似文献
146.
In the scope of this study, boiling points of aqueous solutions of NaCl, DCl, CaCl2, BaCl2, KNO3 and Ca(NO3)2 salts with salt concentrations between 0.5335 and 6.5935 mol kg−1 within 21.332–101.325 kPa pressure range have been determined. Duhring diagrams have been plotted for each solution. In cases, where Raoult's law applied to non-dilute solutions, the deviations from these were determined. 相似文献
147.
Aslantas M Tümer M Sahin E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(1):263-268
The dimeric complex, [C20H20CuN2O2]2, has been prepared and characterized by thermal analysis, IR spectroscopy and single-crystal X-ray diffraction techniques. The Cu atom in the binuclear complex exists in a distorted square-pyramidal configuration, defined by three O atoms and two N atoms. The crystal structure is stabilized by intermolecular C-H...O hydrogen bonding interaction. The electrochemical property of the complex was investigated in CH2Cl2 by cyclic voltammetry at 100 mV s(-1) scan rate. 相似文献
148.
Chang TY Huang M Yanik AA Tsai HY Shi P Aksu S Yanik MF Altug H 《Lab on a chip》2011,11(21):3596-3602
Microarrays allowing simultaneous analysis of thousands of parameters can significantly accelerate screening of large libraries of pharmaceutical compounds and biomolecular interactions. For large-scale studies on diverse biomedical samples, reliable, label-free, and high-content microarrays are needed. In this work, using large-area plasmonic nanohole arrays, we demonstrate for the first time a large-scale label-free microarray technology with over one million sensors on a single microscope slide. A dual-color filter imaging method is introduced to dramatically increase the accuracy, reliability, and signal-to-noise ratio of the sensors in a highly multiplexed manner. We used our technology to quantitatively measure protein-protein interactions. Our platform, which is highly compatible with the current microarray scanning systems can enable a powerful screening technology and facilitate diagnosis and treatment of diseases. 相似文献
149.
Mehmet Y?lmaz 《Tetrahedron》2011,67(43):8255-8263
Manganese(III) acetate based radical cyclization of various fluorinated 1,3-dicarbonyl compounds with 2-thienyl and 2-furyl substituted alkenes produced 3-trifluoroacetyl and 2-trifluoromethyl-dihydrofurans in good yields. The radical cyclizations of 2-methyl-5-[(E)-2-phenylvinyl]furan 2b and 2-[(E)-2-phenylvinyl]thiophene 2c led to the formations of 5-(5-methyl-2-furyl)-4,5-dihydrofuran and 5-(2-thienyl)-4,5-dihydrofuran, respectively. In the reactions of 1,3-dicarbonyls with alkenes, 2-thienyl substituted alkenes formed 4,5-dihydrofurans in higher yields than 2-furyl substituted alkenes. 相似文献
150.
Ali Coruh Faruk Yilmaz Busra Sengez Mustafa Kurt Mehmet Cinar Mehmet Karabacak 《Structural chemistry》2011,22(1):45-56
This work presents the synthesis and characterization of a novel compound, 4-(thiophene-3-ylmethoxy)phthalonitrile (TMP).
The spectroscopic properties of the compound were examined by FT-IR, FT-Raman, NMR, and UV techniques. FT-IR and FT-Raman
spectra in solid state were observed in the region 4000–400 cm−1 and 3500–50 cm−1, respectively. The 1H and 13C NMR spectra were recorded in CDCl3 solution. The UV absorption spectrum of the compound that dissolved in THF was recorded in the range of 200–800 nm. The structural
and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing
B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values
were compared with experimental FT-IR and FT-Raman spectra. The complete assignments were performed on the basis of the experimental
results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method.
Isotropic chemical shifts (13C NMR and 1H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties, such
as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The HOMO and LUMO analyses have been used
to elucidate information regarding charge transfer within the molecule. Comparison of the calculated frequencies, NMR chemical
shifts, absorption wavelengths with the experimental values revealed that DFT method produces good results. 相似文献