نتایج جستجو برای: 13c nmr

تعداد نتایج: 64598  

Journal: :journal of sciences islamic republic of iran 0

aprotic diazotization of anthranilic acid with isoamylnitrite or amylnitrite gave benzenediazonium-2- carboxylate. subsequent thermal decomposition of this diazonium salt (in situ) in 1,2-dichloroethane as a solvent at 85oc and in the presence of 2,5-diethyl-3,4-diphenylcyclopentadienonaes a trapping agent gave 1,4-diethyl-2, 3-diphenylnaphthalene in high yield, after loss of carbon monoxide. a...

Journal: :Journal of the American Chemical Society 2005
Chaiwat Engtrakul Mark F Davis Thomas Gennett Anne C Dillon Kim M Jones Michael J Heben

The reversible protonation of carbon single-walled nanotubes (SWNTs) in sulfuric acid and Nafion was investigated using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopies. Magic-angle spinning (MAS) was used to obtain high-resolution 13C and 1H-13C cross polarization (CP) NMR spectra. The 13C NMR chemical shifts are reported for bulk SWNTs, H2SO4-treated SWNTs, SWNT-Nafion po...

J. Safaei-Ghomi, R. Masoomi

In this research an effective and appropriate method has been developed for one-pot synthesis of new N-phenyl fulleroisoxazoline using Fe3O4@SiO2 nanoparticles as a green magnetically recyclable catalyst. The prepared catalytic samples were characterized by XRD, SEM, FT-IR and VSM. The products have been characterized by physical and spectroscopic data such as IR, 1H NMR, 13C NMR, and MS analyses.

Journal: :Circulation research 1992
R G Weiss S T Gloth R Kalil-Filho V P Chacko M D Stern G Gerstenblith

Although the tricarboxylic acid (TCA) cycle is the prime means of carbon metabolism for energy generation in normal myocardium, the noninvasive quantification of TCA cycle flux in intact cardiac tissues is difficult. A novel approach for estimating citric acid cycle flux using 13C nuclear magnetic resonance (NMR) is presented and evaluated experimentally by comparison with measured myocardial o...

Journal: :iranian journal of pharmaceutical research 0
m iranshahi m ghiadi a sahebkar a rahimi c bassarello s piacente

phytochemical investigation of the dichloromethane extract of the dried roots of ferula badrakema resulted in the identification of one new and six known compounds. known compounds were sesquiterpene coumarins: mogoltacin, feselol, badrakemin acetate, ferocaulidin, conferone and conferol acetate. the new compound was a sesquiterpene, named badrakemonin. the structures of these compounds were el...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1994
mehran chiaci ali mohajeri

conformational properties of n-aryl-1-azacyclooctan-5- ones with a p-methyl, m-methyl, and p-methoxy group as a substituent have been studied by 1h-nmr, 13c-nmr and ir spectroscopies. transannular interaction of the two functional groups have been examined from the ring inversion barriers and the carbonyl vibrational frequencies with reference to the corresponding data of the respective monofun...

2012
Koto Suganuma Ken Horiuchi Hironori Matsuda HN Cheng Akihiro Aoki Tetsuo Asakura

In this work, poly(lactic acid) (PLA) dimer model compounds with different tacticities were synthesized and studied in detail by 1H and 13C nuclear magnetic resonance (NMR) in three solvents, deuterated chloroform (CDCl3)/CCl4 (20/80 v/v), CDCl3 and dimethyl sulfoxide -d6. All of the peaks in the 1H and 13C NMR spectra were assigned with the help of two-dimensional NMR. Although the solvents we...

Journal: :physical chemistry and electrochemistry 0

the electrochemical oxidation of methyl catechol in the presence of 2-thiouracil (as a nucleophile) has beenperformed in aqueous solutions using cyclic voltammetry and controlled-potential coulometric techniques.the electrochemical behavior of methyl catechol in the presence of 2-thiouracil was investigated. theelectrochemical synthesis of this compound has been successfully performed in an und...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
Narasimhamurthy Shanaiah M Aruni Desilva G A Nagana Gowda Michael A Raftery Bryan E Hainline Daniel Raftery

We report a chemical derivatization method that selects a class of metabolites from a complex mixture and enhances their detection by 13C NMR. Acetylation of amines directly in aqueous medium with 1,1'-13C(2) acetic anhydride is a simple method that creates a high sensitivity and quantitative label in complex biofluids with minimal sample pretreatment. Detection using either 1D or 2D 13C NMR ex...

Journal: :iranian journal of pharmaceutical research 0
f fathiazad a delazar r amiri sd sarker

the potential of tobacco waste as a viable source of medicinally important flavonoids like rutin has been investigated. three flavonoids, apigenin, quercetin and rutin, have been isolated from waste tobacco leaves, and their identities have been confirmed by uv-visible, 1h-nmr and 13c-nmr spectroscopy. by using analytical hplc, the amount of rutin present in the tobacco leaves, before and after...

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