نتایج جستجو برای: dynamic 1h nmr
تعداد نتایج: 482449 فیلتر نتایج به سال:
Photochemically induced dynamic nuclear polarization (photo-CIDNP) is a method to hyperpolarize spins using light. In most cases, CIDNP experiments are performed in high magnetic fields and the sample irradiated by light inside resonance (NMR) spectrometer. Here we demonstrate photo-CIDNP hyperpolarization generated Earth’s field under zero- ultralow-field (ZULF) conditions. Irradiating contain...
One novel triterpene cycloartane-type, named hirtinone (1), six protolimonoids - nilocitin (2), dihydronilocitin B (3), melianone epimers (4) and (5), piscidinol A (6) and melianone lactone (7), one tertranortriterpenoid, hirtin (8), and one sesquiterpene, spathulenol (9), were identified in the fruits of Trichilia hirta. The structures were established by 1D and 2D NMR (1H and 13C-NMR, DEPTQ, ...
Two Cd complexes have been prepared by reaction of Cd (II) with 4-(1H-Tetrazol-5yloxy) – phenylamine (HTY) and 2-(1H-Tetrazol) pyridine (HTP) ligands. These new complexes were characterized by IR, UV-Visible, 1H-NMR and 13C-NMR spectroscopies. The changes observed between the FT-IR, H-NMR and UV-Vis spectra of the ligands and complexes allowed to establish the coordination mode of the metal in ...
In the present work we have investigated the macromolecules that contribute to the brain 1H NMR spectrum. The cerebral cortex showed distinct resonances at the uncrowded methyl- and methylene chemical shift scale of the spin-echo 1H NMR spectrum. The peaks at 1.22 and 1.40 ppm (relative to the methyl protons of N-acetyl aspartate at 2.02 ppm) arise from cerebral macromolecules without evidence ...
The number of metabolomic studies has grown steadily over the last twenty years. Among fields application, food sciences are broadly represented. Proton NMR (1H-NMR) is a commonly used technique for metabolomics and particularly suitable wine analysis, because major constituents highly dependent on biotic abiotic conditions. 1H-NMR-based were first to guarantee authenticity wines, more recently...
in this research, the tacticity and microstructure of polyvinyl chloride (pvc) were studied through back bone methylene and methine carbons and protons splitting by carbon (13c nmr), proton (1h nmr) and two-dimensional (2dnmr) nulear magnetic resonance spectroscopy in deuterated etrahydrofuran.polyvinyl chloride was synthesized by emulsion polymerization of vinyl chloride (vcm) under pressure t...
a new series of n-[2-(1h-1,2,3-benzotriazol-1-yl)ethyl]-4-(substitutedphenyl)-3-chloro-2-oxo-1-iminoazetidine, compounds 4(a-j) were synthesized. the structures of all the synthesized compounds were confirmed by chemical and spectral analyses such as ir, 1h nmr, 13c nmr and fab-mass. the compounds 4(a-j) were screened for their antibacterial, antifungal and antitubercular activities and gave ac...
: 1h nmr spectra of a series of enaminones r-co-ch=c(nhch2ph)-r [1, r=ch3; 2, r=c6h5; 3, r=cf3; 4, r=ch2ch2ch2; 5, r=ch2c(ch3)2ch2], were obtained in the presence of trifluoroacetic acid in cdcl3 or dmso-d6 at 28 °c. steric, solvent, electronic and hydrogen bonding effects on the rates of acid-catalyzed nh proton exchanges were investigated. rate constants were calculated by 1h nmr line shape ...
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