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NMR spectroscopy

Tìm thấy 20+ kết quả cho từ khóa "NMR spectroscopy"

Investigation of the hydrogen bond donating ability of 1,8-naphthalenediol by NMR spectroscopy and its use as a hydrogen bonding catalyst

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The progress of the reaction was analyzed by 1 H NMR spectroscopy. The conversion values were determined through the comparison of the integration values for the signal of adduct 16 at 7.04 ppm 46 and the signal of indole (14) at 6.57 ppm.

Liquid state 15N NMR studies of 15N isotope labeled phthalocyanines

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In Pc chemistry, 15 N labeled unsubstituted copper(II) Pc is reported and the isotopic shifts of the IR and Raman bands are studied experimentally and theoretically. 11 Unsubstituted 15 N labeled metal-free Pc has been reported and the proton transfer mechanism has been investigated in solid state using high resolution 15 N and 13 C CPMAS NMR spectroscopy. 12 To the best of our knowledge, for the soluble Pcs liquid state 15 N NMR has not been reported to date..

H'NMR spectral analysis as a new aspect to evaluate the stability of some edible oils

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1 H NMR spectral analysis as a new aspect to evaluate the stability of some edible oils. 1 H NMR spectroscopy;. Extra virgin olive oil;. Sunflower oil. Abstract Oxidative stability is one of the most important indicators for maintaining the quality of edible oils. 1 H NMR fingerprinting is used to evaluate the stability of edible oils at room temper- ature.

Metal- and solvent-free preparation of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives catalysed by deep eutectic solvents

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A typical procedure for the synthesis DES: a mixture of ChCl and phenol with a 1:2 molar ratio was magnetically stirred at 100 o C until a colourless liquid was obtained.. 13 C-NMR spectroscopy. 1 H-NMR (500 MHz, DMSO-d 6 ) δ m, 2H), 7.14 (t, J=7.8 Hz, 4H m, 6H m, 1H), 3.82 (td, J=4.9, 2.4 Hz, 2H), 3.43 (m, 2H), 3.13 (s, 9H). 13 C-NMR (125 MHz, DMSO-d 6 ) δ 157.85 (s), 129.78 (s), 119.20 (s), 115.73 (s m), 55.57 (s m)..

Convenient synthesis of new polysubstituted isoindole-1,3-dione analogues

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The configuration of the triacetate 10 was confirmed by 1 H NMR spectroscopy.. Cis-configuration of the H 5 /H 6 and H 6 /H 7 adjacent protons was supported by the small coupling constants, J 5,6 and J 6,7 = 2.2 Hz.. The exact configuration of the triacetate 10 was confirmed by differential 1 H NMR-NOE measurements (Figure 3).

Synthesis and characterization of alkyl-methacrylate-maleic anhydride copolymer for use as a biodiesel flow improver

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We see that all typical groups in the alkyl-methacrylate- maleic anhydride copolymers are fully characterized by FTIR spectra.. 1 H-NMR spectra of alkyl methacrylate - maleic anhydride copolymers. The structure of alkyl methacrylate - maleic anhydride copolymers is also confirmed by 1 H-NMR spectroscopy..

In silico ADME predictions and in vitro antibacterial evaluation of 2-hydroxy benzothiazole-based 1,3,4-oxadiazole derivatives

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The proposed structures of the synthesized compounds were confirmed with different analytical techniques, such as IR, 1 H NMR, and 13 C NMR spectroscopy, an elemental analyzer, and mass spectrometry.. All of the spectral data were in agreement with the proposed structures of the synthesized compounds..

Synthesis and characterization of biodegradable palm palmitic acid based bioplastic

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FTIR spectrum of (a) MP and (b) DMTDM.. 1 H NMR spectrum of DMTDM.. 1733 cm –1 , for DMTHM, PHTDM and PDTDM, respectively, are assigned to functional groups of esterified carbonyl C=O. The peaks at 2922–2856 cm –1 indicate CH 2 and CH 3 stretching vibration of DMTHM, PHTDM and PDTDM. NMR analysis of PHTDM and PDTDM. The 1 H NMR spectroscopy displays the main signal assignments of PHTDM and PDTDM as shown in Figure 15.

Nghiên cứu công nghệ tổng hợp Sorbitol từ Glucoza bằng phương pháp gián đoạn

000000105501-TT.pdf

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The structure of sorbitol was elucidated by spectroscopic methods (IR, EI-MS, NMR). The structural elucidation of the reaction product with results of IR, MS, NMR spectroscopy methods and references have been suggested that the reaction product is sorbitol

Synthesis, characterization and catalytic properties of cationic N-heterocyclic carbene silver complexes

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Stability of the silver complexes was confirmed by 1 H NMR spectroscopy. d = 10.11 (s, 2H, NCHN m, 4H, Ar-H m, 4H, Ar-H), 6.73 (d, 4H, J = 1.4 Hz, Ar-H), 6.47 (s, 2H, Ar-H), 5.68 (s, 4H, NCH 2. d = 10.17 (s, 2H, NCHN), 8.11 (dd, 2H, J 1 = 8.6 Hz, J 2 = 4.5 Hz, Ar-H m, 2H, Ar-H), 7.71–. d = 7.62 (t, 8H, J = 9.1 Hz, Ar-H), 7.34 (s, 8H, Ar-H), 6.76 (s, 12H, Ar-H), 5.55 (s, 8H, NCH 2.

Novel bis(aminoalcohol)oxalamide organogelators and their diglycolylamide analogs: Evaluation of gelation efficiency in various organic fluids

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The purity of the products was proved by elemental analysis and TLC, as well as by IR, 1 H NMR, and 13 C NMR spectroscopy.. 0.3% of the theoretical values. A Bruker AV-400 digital FT-NMR spectrometer was used to record 1 H NMR (400 MHz) and 13 C NMR (100 MHz) spectra in the solvents mentioned. General procedure for the synthesis of aminoalcohols.

Comparative study of microwave-assisted and conventional synthesis of ibuprofen-based acyl hydrazone derivatives

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The chemical structures of the synthesized compounds were characterized by IR, 1 H NMR, and APT-NMR spectroscopy.. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) used in the treatment of a number of arthritic diseases. One of the strategies adopted to minimize the side effects of NSAIDs includes the synthesis of new, safer, and potent hybrid compound-containing NSAIDs. Hydrazone derivatives derived from anti-inflammatory agents have been studied in the literature.

Synthesis, spectroscopic studies, and antioxidant activities of novel thio/carbohydrazones and bis-isatin derivatives from terephthalaldehyde

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All the synthesized compounds were elucidated using IR, 1 H NMR, and 13 C NMR spectroscopy and elemental analysis. The in vitro antioxidant activity of all the compounds was measured by the 1,1-diphenyl-2-picryl hydrazyl (DPPH. Antioxidant activity. In order to evaluate the antioxidant activity of the newly synthesized compounds, we used DPPH in ethanol at a concentration of 55 µM. Stock solutions of the compounds (250 µM) were prepared in DMSO.

Biochemistry, 4th Edition P57

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FIGURE 17.15 With NMR spectroscopy, one can observe the metabolism of a living subject in real time. These NMR spectra show the changes in ATP, creatine-P (phos- phocreatine), and P i levels in the forearm muscle of a human subjected to 19 minutes of exercise. FIGURE 17.16 Fractionation of a cell extract by differential centrifugation.

Synthesis and characterization of benzodioxinone mono-telechelics and their use in block copolymerization

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In addition to FT-IR investigations, the 1 H-NMR spectroscopy gives more detailed information about the chemical structures of mPEG-DPh-Bd and mPEG-DMe-Bd monotelechelics (Figure 2). In both cases, the characteristic peaks (e+f) of mPEG were clearly detected around 3.31–3.92 ppm, while the aromatic and aliphatic peaks of benzodioxinones also appeared at and 4.76 ppm.

Synthesis and characterization of new chromogenic substrates for exoglycosidases: α-glucosidase, α-mannosidase, and β -galactosidase

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The structure of the synthetic glycosides was confirmed by NMR spectroscopy. The 3 chromogenic glycosides proved to be remarkably good substrates for enzymes of animal, vegetal, or microbial origin.. It played an essential role in the experiments in this paper.

Synthesis and evaluation of catecholase activities of metal complexes of 1,4-substituted piperazine Mannich base of 4-acetamidophenol

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The identification of 3,5-DTBQ by 1 H NMR spectroscopy [ 1 H NMR (CDCl 3 , 300 MHz): δ H = 1.22 (s, 9H), 1.27 (s, 9H), 6.22 (d, J = 3.0 Hz, 1H), 6.92 (d, J = 3.0 Hz, 1H)] and H 2 O 2 through iodometric titration points to the fact that the mechanism is as follows: one-electron transfer from catechol to the Cu(II) centre results in the formation of semiquinone radical and the Cu(II) centre is reduced to Cu(I).

Maximizing Ethanol Production by Engineered Pentose-Fermenting Zymomonas mobilis

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HPLC and NMR spectroscopy and evaluate ethanol production by the new strains on mixed sugars.. Develop a structured kinetic model for the integrated pathway network and identify potential improvements through dynamic simulations.. ü Integrate into the Zymomonas genome.. into the Zymomonas genome.. xylose assimilation genes ( xylA, xylB. pentose-phosphate pathway genes (tal, tkt. arabinose assimilation genes ( araA, araB, araD ) pentose-phosphate pathway genes (tal,tkt. Homologous Recombination.

Synthesis and catalytic activity of ionic palladium N-heterocyclic carbene complexes

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The formation of ionic Pd(II)-NHC complexes was confirmed by 1 H NMR spectroscopy, which showed the existence of the NCH N proton on the benzimidazolium cation.. Furthermore, a significant downfield shift signal of the coordinated NC N carbon of NHC ligands to palladium metal and a slight downfield shift signal of NCHN emerging in one 13 C NMR spectrum confirmed the formation of ionic palladium complexes.

CÂU HỎI TRẮC NGHIỆM (CÓ ĐÁP ÁN

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A. a triplet Câu 43: How many signals would you expect to see in the 1H NMR spectrum of 1- bromopropane and 2-bromopropane? A. Câu 44: How many signals would you expect to see in the 1H NMR spectrum of 2- methylpropene? A. 5 Câu 45: Which of the following compounds is frequently used as an internal reference in 1 H NMR spectroscopy? A. (CH3)2CBrCH2Br Câu 47: In what region of the 1H NMR spectrum would you expect to find signals that are due to methyl groups?