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EN
Transition metal complexes of the type ML1 [Where M= Co(II),Ni(II),Cu(II) and Zn(II), L= Schiff base of 5 nitro-salicylaldehyde and p- anisidine were characterized by using&ensp1H NMR ,TGA, Diffused reflectance and ESR spectroscopy. On the basis of above studies Co(II), Ni(II) shows tetrahedral structure, Cu(II) and Zn(II) shows square planar structure.
EN
Transition metal complexes of the type ML.nH2O [Where M= Co(II),Ni(II),Cu(II) and Zn(II), L= Schiff base of 5 nitro salicylaldehyde and anthranalic acid , n= 0,1 …..] were characterized by using&ensp1H NMR ,TGA, Diffused refluctance and ESR spectroscopy. On the basis of above studies Co(II), Ni(II) shows tetrahedral structure, Cu(II) shows binuclear structure and Zn(II) shows square planar structure.
PL
Zastosowanie metod spektroskopowych w chemii polimerów pozwala na uzyskanie niezbędnych informacji przy identyfikowaniu struktury chemicznej związków i tym samym na badanie różnych procesów, począwszy od syntezy inicjatorów, ich zachowania się w różnych warunkach (np. w reakcji rozpadu), poprzez badanie pozostałych substratów oraz produktów polimeryzacji, a także badanie innych procesów - modyfikacji czy destrukcji polimerów.
EN
The utilization of spectroscopic methods in polymer chemistry allows obtaining the necessary information to identify the chemical structure of compounds and moreover different processes studies, starting from initiator synthesis, their behaviour at various conditions (e.g. during thermal decomposition), through the other polymerization substrates and products study, and also other processes - polymers modification or destruction investigations.
PL
Przedstawiono wyniki badań wpływu wymiarów i kształtu cząsteczek oligomerów: dimeru heksametylosiloksanu (HMDS), trimeru heksametylocyklotrisiloksanu (HMCTS), tetrameru oktametylocyklotetrasiloksanu (OMCTS) i liniowego oligodimetylosiloksanu o lepkości kinetycznej ok. 10 cSt (PDMS10), a także dwu polidimetylosiloksanów o strukturze liniowej i o lepkości ok. 300 cSt (PDMS300) bądź ok. 1000 cSt (PDMS1000) na czas relaksacji podłużnej (T1) w metodzie 1H NMR. Próbki przygotowywano rozpuszczając wymienione substancje w mieszaninie tetrachlorku węgla oraz deuterowanego benzenu. Stwierdzono, że czas T1 nie zależy w sposób istotny od stężenia analitu w próbce i jest, praktycznie biorąc, niezależny od wzajemnej proporcji stosowanych rozpuszczalników. Zaobserwowano, że wzrost długości łańcucha PDMS powoduje skrócenie T1, a cyklizacja cząsteczki nie wpływa na jego wartość. Badania wykazały, że uzyskanie wiarygodnych wyników oznaczań ilościowych PDMS wymaga zastosowania optymalnych wartości parametrów rejestracji widm, a w szczególności czasu opóźnienia (td) i czasu akwizycji danych (ta), które powinny wynosić odpowiednio 15 s i 5 s.
EN
The results of investigations of the effects of size and shape of molecules of oligomers: hexamethyldisiloxane (HMDS) dimer, octamethylcyclotetrasiloxane (OMCTS) tetramer and polydimethylsiloxane, characterized by kinetic viscosity ~10 cSt (PDMS10), as well as of two linear polydimethylsiloxanes [one of viscosity about 300 cSt (PDMS300) the other of about 1000 cSt (PDMS1000)] on longitudinal relaxation time (T1) in 1H NMR method were presented. The samples were prepared by dissolution of the substances mentioned in the mixture of carbon tetrachloride with deuterated benzene (Table 2). It was found that T1 time did not significantly depend on the analyte concentration in the sample and was practically independent on the mutual ratio of the solvents used. It was observed the increase in the chain length of PDMS caused T1 decrease while cyclization of the molecule did not influence its value (Table 2). The investigations showed that to obtain credible results of quantitative PDMS determination it was necessary to use the optimal values of spectra registration parameters, especially delay time (td) and data acquisition time (ta) which should be 15 s and 5 s, respectively.
PL
Kontynuując badania przedstawione w części I, przeprowadzono analizę składu chemicznego produktów ciekłych uzyskanych w wyniku odgazowania węgli w różnych temperaturach. Zastosowano metodę 1H NMR. Wykazano związki między ciśnieniem rozprężania węgli z tych samych kopalń a strukturą chemiczną smół
EN
As the continuation of studies presented in Part I of the paper it was carried out analysis of chemical composition of low-temperature tar and coke oven tar by 1H NMR analysis. It was proved that in the case of low-temperature tar alkyl-aromatic compounds contain long-chain and branched substituents, whereas in the case of coke oven tar substituents are smaller and less branched
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EN
High-resolution 1H NMR spectroscopy of body fluids has proved to be very useful in diagnostics of inherited metabolic diseases, whereas 13C NMR remains almost unexploited. In this paper the application of 13C NMR spectroscopy of fivefold concentrated urine samples for diagnosis of selected metabolic diseases is reported. Various marker metabolites were identified in test urine samples from 33 patients suffering from 10 different diseases, providing information which could be crucial for their diagnoses. Spectra were accumulated for 2 h or overnight when using spectrometers operating at 9.4 or 4.7 T magnetic fields, respectively. Interpretation of the measurement results was based on a comparison of the peak positions in the measured spectrum with reference data. The paper contains a table with 13C NMR chemical shifts of 73 standard compounds. The method can be applied individually or as an auxiliary technique to 1H NMR or any other analytical method.
EN
This study gives updated information on the isolation of ulvan from green alga Ulva fasciata Delile in Egypt through isolation and chemical characterization of sulfate polysaccharides by two sequential extraction steps using different solvents; distilled water, HCl and Na2EDTA forming fraction I (F-I). Fraction II (F-II) was obtained from remaining seaweeds using NaOH to give FDWNaOH, FHClNaOH, and FEDTANaOH. All products obtained were tested for their biological activities. The highest polysaccharides total extraction yield was 11.8% for water extract (F-I and F-II). The highest protein content was found in FEDTANaOH (2.44%). The highest sulfate content was recorded for F-I (HCl) (21.38%). Total carbohydrates range was 11.99–63.90% for F-I and 15.06–76.65% for F-II. Monosaccharides; galactose, rhamnose, and uronic acid were detected at all fractions, with concentrations varying from 0.11 to 1.34%, from 0.61 to 1.81% and from 11.06 to 19.30%, respectively. 1H NMR of F-II demonstrated the signals of ring and methyl protons of polysaccharide. The appearance of the stretching bands of the sulfate ester (C-O-S) and sulfate groups (S=O) in the FT-IR spectrum of FHClNaOH confirmed the presence of sulfated polysaccharides, typical of ulvan. The microbial species Vibrio damsela was the most susceptible to FDWNaOH, followed by Aeromonas hydrophila and Vibrio fluvialis with inhibition zones of 30, 22, 22 mm at 150 mg/ml, respectively. FDWNaOH was the most effective fraction having antifouling property. The highest antioxidant activity was observed for F-IHCl followed by FDWNaOH. At concentrations 25 and 50 mg/l, FEDTANaOH displayed the highest anti-inflammatory activity (94.0 and 91.40%, respectively).
EN
The crystal and molecular structure of the title compound has been determined by X-ray analysis. This compound crystallizes in the P2-1/c space group with cell parameters: a= 9.325(2), b=15.158(3), c=14.102(3) A, beta=106.40(3)degree and with four C14H19N(+/2)xC6H7O(-/4) formula units in the unit cell. The structure contains DMANH(+) cations with a short asymmetric intramolecular N-H...N hydrogen bond (N...N 2.595(2) A) and CBDC(-) monoanions with a short intramolecular O-H...O hydrogen bond (O...) 2.412(3) A). The ionic character of he very strog (NHN)(+) and moderately strong (OHO)(-) hydrogen bonds has been derived from IR spetroscopy. The (1)H NMR spectrum measured in acetonitrile solution is similar to that in the solid state.
EN
A range of inborn metabolic diseases result in abnormal accumulation of acylglycines in body fluids. Therefore, detection of these metabolites is important for diagnostic purposes. 1H and 13C NMR spectroscopies have successfully been applied for both qualitative and quantitative determinations of various acylglycines in urine samples from patients suffering from metabolic diseases connected with excretion of these compounds. Various acylglycines were identified in test urine samples from 15 patients suffering from five different metabolic diseases, providing information which could be crucial for their diagnoses. The paper reports complete 1H and 13C NMR data of 11 acylglycines, which is essential for this type of NMR analysis of body fluids. NMR spectroscopy has been proven effective in determining the presence as well as the levels of acylglycines in urine. The proposed method is rapid, simple and requires minimal sample treatment.
10
Content available remote Hydrolysis of silica sources: APS and DTSACl in microencapsulation processes
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EN
The process of formation of silica shells around emulsion droplets was investigated. The 1H-NMR spectroscopy was applied to follow the silica shell formation around emulsion droplets by hydrolysis and condensation of selected silanes in the emulsion system. (3- aminopropyl) triethoxysilane (APS) and dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DTSACl) were used as silica sources in microencapsulation process. The NMR analysis revealed strong dependence of the hydrolysis reaction rate on pH. Obtained information allowed selecting the optimal conditions for the formation of the capsules with silica shells. The obtained capsules' suspensions were stable for several weeks.
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EN
9-Chloro-2,4-(un)substituted acridines (1) on condensation with sulpha- diazine, sulphathiazole, and sulphaacetamide gave condensation products 3a-h. 3-Aryl-4-phenyl-2-imino-4-thiazolines (4) on condensation with 9-chloro-2,4-(un)substituted acridines (1) gave condensation products 5a–5o. Both 3a–3h and 5a–5o were purified by crystallization or by chromatography. Structures assigned to 3a–3h and 5a–5o are supported by correct spectral data. Antiinflammatory and analgesic activity screening of 3a, 3e, 3f and 5a–5c, 5e, 5g, 5i, 5m, 5n were carried out using carrageenin induced paw oedema and phenyl quinone writhing assay. Some of the compounds exhibited interesting antiinflammatory or analgesic activities.
EN
Formation of complexes of A18C6-Dns and metal cations (Ca2+, Sr2+, Ba2+ and Mg2+) in acetonitrile has been studied by NMR, absorption and fluorescence spectroscopy and PM5 semi-empirical methods. A18C6-Dns forms stable complexes with Ca2+, Sr2+ and Ba2+ cations. The stability constants of various complexes are determined by different methods and their structures are visualised by the PM5 semi-empirical calculations.
EN
The charge-transfer complexation between octathia-24-crown-8 (OT24C8) and iodine in chloroform solution was studied spectrometrically at various temperatures. The molar absorptivities and formation constants of the resulting 1:1 complex were determined. The formation of the OT24C8-I2 complex was also confirmed by 1H NMR spectrometry. The enthalpy and entropy of the charge-transfer complexation were determined from the temperature dependence of the formation constant, as Delta H graduate = -31.0 + - 0.5 kJ mol-1 and Delta S graduate = -84 + - 6 J mol-1K-1.
EN
The structures of some nitrosubstituted meso-tetraarylporphyrins were determined by a simple comparison of their 1H NMRspectra, and confirmed by NOE experiments. On the basis of these investigations it was found that in the meso-tetraphenylporphyrin (meso-TPP) and its 3-methoxy, 3-methyl, and 3-chloro-substituted derivatives (in the meso-aryl rings), the electrophilic nitration occurred in position 4-.
EN
N,N'-Bis(methyl 3,4,6-tri-O-acetyl-2-deoxy-b-D-glucopyranosid-2-yl)urea 1 and its N'-nitroso derivative 2 were synthesized from methyl 2-amino-3,4,6-tri-O-acetyl-2-deoxy-b-D-glucopyranoside and di(4-nitrophenyl)carbamate. The nitrosation was carried out using N2O3 in dichloromethane. The structure of compounds was analyzed by 1H, 13C, 15N NMR in CDCl3 and 13C CP MAS in the solid state. The assignments of resonances were done by COSY1H, 13C, HETCOR and the 1H, 15N2D correlation spectroscopy. Compound 1 gives one set of 1H/13C resonances in solution, but exhibits polymorphism in the solid state.
EN
1Hand 13CNMRspectra of isoguanine (2-hydroxyadenine) and 8-oxoadenine inH2Oand DMSO-d6 solutions of various acidity have been interpreted using arguments based on the results of several 1D and 2D NMR experiments and theoretical DFT-based calculations. The collected data for H2O solutions can serve for identification of these compounds in body fluids during medical analysis. The 1H and 13C NMR spectra of the investigated compounds in DMSO-d6 solutions have provided information on their tautomeric forms and the mobility of their exchangeable protons.
PL
Zbadano wpływ dodatku nanonapełniacza węglowego (ekspandowanego grafitu) na przebieg syntezy PETG (kopolimeru PET-ran-PCT), morfologię nanokompozytu oraz jego przemiany fazowe. Badany nanokompozyt zawierał 0,1 % mas. ekspandowanego grafitu (EG) w postaci pojedynczych płaszczyzn grafenowych oraz (w większości) luźno złączonych paczek grafenów. Nie stwierdzono wpływu nanocząstek EG na przemiany fizyczne w kopolimerze PET-ran-PCT. Na termogramach układu zawierającego 20 lub 30 % mol. PCT nie zaobserwowano piku topnienia ani krystalizacji. Na podstawie analizy ilościowej produktów ubocznych metodą chromatografii gazowej ustalono, że skład otrzymanego polimeru był zgodny z obliczonym na podstawie stechiometrycznych ilości głównych składników. Budowę chemiczną zsyntezowanego kopolimeru potwierdzono przy użyciu spektroskopii 1H NMR.
EN
In this work, the effect of the addition of carbon nanofiller (expanded graphite) on the process of synthesis of PETG (PET-ran-PCT copolymer), morphology of the resulting nanocomposite and its phase transitions has been studied. The examined PETG contained 0.1 wt. % expanded graphite (EG) in the form of single graphene sheets and (predominantly) loosely assembled graphene bundles, as it was observed by SEM analysis (Fig. 4a). No influence of EG nanoparticles on the physical changes in the PET-ran-PCT copolymer was found. DSC thermograms of PETG with 20 or 30 mol. % PCT content did not show melting or crystallization peaks (Fig. 5). The results of quantitative analysis of by-products using gas chromatography indicated that the composition of the prepared polymer was in accordance with that calculated from the stoichiometric amounts of main components. Additionally, the molecular structure of synthesized copolymers was confirmed by 1H NMR spectroscopy (Fig. 3). The signals in the range 2,41—1,63 ppm (peak d) indicated the presence of cis-trans isomers corresponding to cyclohexanedimethanol in the copolymer.
EN
The stable E- and Z-isomers of 10-membered azocrown ether have been isolated and studied by X-ray, 1H NMR and UV-Vis methods. Their structures in a solid state indicate the stretched conformation for trans-isomer and unstressed for cis-isomer. The concerted effect of azo-group _-conjugation with benzene residue and steric strain of molecular conformation results in the observed stability of isomers.
19
Content available remote Interaction of fibrinogen with nanosilica
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EN
Interaction of human plasma fibrinogen (HPF) with fumed nanosilica A-300 in a phosphate buffer solution (PBS) was studied using 1H NMR spectroscopy with layer-by-layer freezing-out of bulk and interfacial water in the temperature range of 210–273 K, TSDC (90 T FTIR, and UV spectroscopy methods. An increase in concentration of HPF in the PBS leads to a decrease in amounts of structured water (frozen at T FTIR and UV spectra show that the HPF adsorption on silica leads to structural changes of the protein molecules. These changes and formation of hybrid HPF/A-300 aggregates can increase the rate of clotting that is of importance on nanosilica application as a component of tourniquet preparations. [...]
EN
Structural characteristics of synthesized ordered mesoporous silicas MCM-41, MCM-48 and SBA-15 were studied using XRD, nitrogen adsorption and FTIR methods. Pure water and mixtures with water/benzene and water/chloroform-d adsorbed onto silicas were studied by 1H NMR spectroscopy with layer-by-layer freezing-out of bulk and interfacial liquids. Concentrated aqueous suspensions of MCM-48 and SBA-15 were studied by thermally stimulated depolarization current (TSDC) method. Benzene and chloroform-d can displace a portion of water to broad pores from the pore walls and from narrower pores, especially in the case of a large excess of an organic solvent. This process is accompanied by diminution of both interaction energy of water with an adsorbent surface and freezing temperature depression of adsorbed water. The effect of nonpolar benzene on pore water is much stronger than that of weakly polar chloroform-d. Modifications of the Gibbs-Thomson relation to describe the freezing point depression of mixtures of immiscible liquids confined in pores allow us to determine distribution functions of sizes of structures with unfrozen pore water and benzene. [...]
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