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71.
72.
Murat Aydemir Nermin Meric Akın Baysal Bahattin Gümgüm Mahmut Toğrul Yılmaz Turgut 《Tetrahedron: Asymmetry》2010,21(6):703-710
Hydrogen-transfer reduction processes are attracting increasing interest from synthetic chemists in view of their operational simplicity. The new chiral C2-symmetric ligands N,N′-bis-[(1S)-1-sec-butyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 1 and N,N′-bis-[(1S)-1-phenyl-2-O-(diphenylphosphinite)ethyl]ethanediamide, 2 and the corresponding ruthenium complexes 3 and 4 have been prepared and their structures have been elucidated by a combination of multi-nuclear NMR spectroscopy, IR spectroscopy, and elemental analysis. 1H–31P NMR, DEPT, 1H–13C HETCOR, or 1H–1H COSY correlation experiments were used to confirm the spectral assignments. The catalytic activity of complexes 3 and 4 in transfer hydrogenation of acetophenone derivatives by iso-PrOH has also been studied. Under optimized conditions, these chiral ruthenium complexes serve as catalyst precursors for the asymmetric transfer hydrogenation of acetophenone derivatives in iso-PrOH and act as excellent catalysts, giving the corresponding chiral alcohols in 99% yield and up to 75% ee. This transfer hydrogenation is characterized by low reversibility under these conditions. 相似文献
73.
Erhan Temur İsmail Hakkı Boyacı Uğur Tamer Hande Unsal Nihal Aydogan 《Analytical and bioanalytical chemistry》2010,397(4):1595-1604
A very sensitive and highly specific heterogeneous immunoassay system, based on surface-enhanced Raman scattering (SERS) and
gold nanoparticles, was developed for the detection of bacteria and other pathogens. Two different types of gold nanoparticles
(citrate-stabilized gold nanosphere and hexadecyltrimethylammonium bromide (CTAB)-stabilized gold nanorod particles) were
examined and this immunoassay was applied for the detection of Escherichia coli. Raman labels were constructed by using these spherical and rod-shaped gold nanoparticles which were first coated with 5,5′-dithiobis(2-nitrobenzoic
acid) (DTNB) and subsequently with a molecular recognizer. The working curve was obtained by plotting the intensity of the
SERS signal of the symmetric NO2 stretching of DTNB at 1,333 cm−1 versus the concentration of the E. coli. The analytical performance of gold particles was evaluated via a sandwich immunoassay, and linear calibration graphs were
obtained in the E. coli concentration range of 101–105 cfu/mL with a 60-s accumulation time. The sensitivity of the Raman label fabricated with gold nanorods was more than three
times higher than spherical gold nanoparticles. The selectivity of the developed sensor was examined with Enterobacter aerogenes and Enterobacter dissolvens, which did not produce any significant response. The usefulness of the developed immunoassay to detect E. coli in real water samples was also demonstrated. 相似文献
74.
Two non-linear azide containing heteronuclear complexes: crystal structure and thermal decomposition
S. Öz R. Kurtaran C. Arıcı Ü. Ergun F. N. Dinçer Kaya K. C. Emregül O. Atakol D. Ülkü 《Journal of Thermal Analysis and Calorimetry》2010,99(1):363-368
Bis-N,N′(salicylidene)-2,2′-dimethyl-1,3-propanediamine (LDMH2) has a high tendency to form polynuclear complexes. Two trinuclear complexes were obtained using this ligand and azide ions; (CuLDM)2 · Mn(N3)2 · (DMF)2, [(C19H20N2O2Cu)2 · Mn(N3)2 · (C3H7NO)2] and (CuLDM)2 · Cd(N3)2 · (DMF)2, [(C19H20N2O2Cu)2 · Cd(N3)2 · (C3H7NO)2]. The structures were identified with X-ray methods. TG and DSC methods were also employed to these complexes. Studies showed the (CuLDM)2 · Mn(N3)2 · (DMF)2 and (CuLDM)2 · Cd(N3)2 · (DMF)2 to be non-linear. Also μ-bridges were not encountered for the azide ions but were seen to form between the Cu and other metal via phenolic oxygens. Thermal analysis showed exothermic degradation of the azide ions destroying the trinuclear structure. Although azide containing structures show explosive characteristics, this was not observed for the present compounds. 相似文献
75.
A method has been developed for the spectrophotometric determination of selenium(IV) using 4-methyl-o-phenylenediamine (MOPDA) as a chromogenic reagent. In hydrochloric acid media at about pH 2, MOPDA forms a piazselenol complex with selenium(IV), which gives an absorption maximum at 332 nm. After transfer of the formed piazselenol complex into organic phase with n-hexane, the absorbance of the piazselenol complex was measured by a UV-Vis spectrophotometer. The effective parameters of the experimental conditions such as pH, formation time of the complex, amount of MOPDA, ionic strength, volume of sample and effects of diverse ions, were investigated. The detection limit of the proposed method was found to be 0.95 μg/L Se(IV) (n = 14, 3σ). The method was successfully applied to tap water, sea water and wastewater samples from washings of flue gases with satisfactory results. 相似文献
76.
Ahmet Colak Ender Cekirge Serdar Karaböcek Aslıgül Küçükdumlu Nagihan Sağlam Ertunga Melek Col Rza Abbasoğlu 《Chemical Papers》2009,63(5):554-561
Nucleolytic activities of some new oxime-type ligand complexes were investigated by neutral agarose gel electrophoresis. Analysis
of the cleavage products in agarose gel indicated that all complexes used converted supercoiled pUC18 plasmid DNA to its nicked
or linear form. It was found that nucleolytic activities of the complexes depend on the complex concentration, reaction time
and the presence of a cooxidant (magnesium monoperoxyphthalate, MMPP) in the reaction mixture. However, the complexes cleaved
pUC18 plasmid DNA at all investigated pH values. Nucleolytic activities of complexes were investigated for different complex
concentrations (0.1–100 μmol L−1), pH values (6.0–10.0) and reaction times (0–60 min). Molecular modeling studies performed by the Hyperchem Software together
with DNA-binding studies showed that planar sites of the complexes intercalated into double stranded DNA. It can be concluded
that all oxime-type ligand complexes used can be evaluated as nuclease mimics. 相似文献
77.
A new chelating resin, 1-(2-pyridylazo)-2-naphthol (PAN) coated Amberlite XAD-1180 (AXAD-1180), was prepared and used for
the preconcentration of Cd(II), Mn(II), Ni(II), Pb(II) and Zn(II) ions prior to their determination by flame atomic absorption
spectrometry (FAAS). The optimum pH for simultaneous retention of the elements and the best elution means for their simultaneous
elution were pH 9.5 and 3 M HNO3, respectively. The sorption capacity of the resin was found to be 5.3 mg/g for Cd and 3.7 mg/g for Ni. The detection limits
for Cd(II), Mn(II), Ni(II), Pb(II) and Zn(II) were 0.7, 10, 3.1, 29 and 0.8 μg/L, respectively. The effects of interfering
ions for quantitative sorption of the metal ions were investigated. The preconcentration factors of the method were in the
range of 10–30. The recoveries obtained were quantitative (≥95%). The standard reference material (GBW07605 Tea sample) was
analysed for accuracy of the described method. The proposed method was successfully applied to the analysis of various water,
urea fertilizer and tea samples.
The article is published in the original. 相似文献
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