Results 241 to 250 of about 494,170 (294)
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Research In Experimental Medicine, 1985
31P-NMR spectra were obtained from adenosine-5'-tetraphosphate under a variety of conditions and the four discernible resonances assigned. The pK-value of the metal-free compound was determined to be 6.4, the pK-value of the Mg2+ complex to be 5.3. The dissociation constant for the AP4 X Mg2+ complex was estimated to be 10(-4) M from the downfield ...
W, Klaus, P, Rösch, R S, Goody
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31P-NMR spectra were obtained from adenosine-5'-tetraphosphate under a variety of conditions and the four discernible resonances assigned. The pK-value of the metal-free compound was determined to be 6.4, the pK-value of the Mg2+ complex to be 5.3. The dissociation constant for the AP4 X Mg2+ complex was estimated to be 10(-4) M from the downfield ...
W, Klaus, P, Rösch, R S, Goody
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The NMR spectra of the porphyrins: 24—The NMR spectra of some tetraarylchlorins
Organic Magnetic Resonance, 1983AbstractThe synthesis and complete assignment of the 1H NMR spectra of 5‐(o‐pivaloylaminophenyl)‐10,15,20‐triphenylporphyrin (PIVTPP) and its two chiral dihydro adducts 3,4‐dihydro‐(PIVPTPC‐I)‐ and 7,8‐dihydr‐ (PIVPTPC‐II)‐porphyrins are reported. The use of the zinc complexes of the chlorins as chiral shift reagents with optically active bases is ...
Raymond J. Abraham +2 more
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NMR spectra of estrogen catechols
Tetrahedron, 1968Abstract The NMR of various estrogen catechol derivatives were observed in CDCl 3 and DMSO. The chemical shifts of the aromatic protons permit the ready assignment of structure to isomeric monoderivatives. The reasons for the different chemical shifts of the two aromatic protons in 2-hydroxyestrogens are discussed.
J, Fishman, J S, Liang
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NMR spectra of fluorinated carbohydrates
Carbohydrate Research, 2000Recent advances in structural and conformational analysis of fluorinated carbohydrates by NMR spectroscopy are reviewed. Characteristic 1H, 13C, and 19F NMR chemical shifts and coupling constants for selected examples are given and the spectral data of a series of fluorinated carbohydrates were collected in continuation of the review of Csuk and ...
M, Michalik, M, Hein, M, Frank
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2022
This chapter details the features of nuclear magnetic resonance (NMR) spectra. It starts with the chemical shift of a nucleus carrying the difference between its resonance frequency and that of a reference standard. The resonance frequency of a magnetic nucleus is affected by its electronic environment and the presence of nearby magnetic nuclei.
Peter Atkins +2 more
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This chapter details the features of nuclear magnetic resonance (NMR) spectra. It starts with the chemical shift of a nucleus carrying the difference between its resonance frequency and that of a reference standard. The resonance frequency of a magnetic nucleus is affected by its electronic environment and the presence of nearby magnetic nuclei.
Peter Atkins +2 more
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ChemInform, 2007
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Erkki Kolehmainen +2 more
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AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Erkki Kolehmainen +2 more
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The Journal of Chemical Physics, 1961
The NMR spectra of glycidaldehyde were measured at 40 and 60 Mc/sec. [Complex chemical formula] These complicated spectra of four interacting protons were analyzed by two methods: the ABKY approximation and the iterated ABCD solution. The various mathematical techniques developed should prove useful in the analyses of other complicated spin resonance ...
C. A. Reilly, J. D. Swalen
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The NMR spectra of glycidaldehyde were measured at 40 and 60 Mc/sec. [Complex chemical formula] These complicated spectra of four interacting protons were analyzed by two methods: the ABKY approximation and the iterated ABCD solution. The various mathematical techniques developed should prove useful in the analyses of other complicated spin resonance ...
C. A. Reilly, J. D. Swalen
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NMR spectra of halopermethylpolysilanes
Journal of Organometallic Chemistry, 1974Abstract Proton NMR spectra were determined for the series X(SiMe2)nX (n = 3, 4, 6 and X F, Cl, I) and Me(SiMe2)6X. Fluorine-19 NMR spectrafor the fluorosilanes of these series were also determined. The chemical shift of the methyl protons of the SiMe2X group appears at higher field as the chain length increases.
W.G. Boberski, A.L. Allred
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Exact Classification of NMR Spectra from NMR Signals
ICASSP 2024 - 2024 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)Nuclear magnetic resonance (NMR) spectroscopy is routinely used to study the properties of matter. Therefore, different materials can be classified according to their NMR spectra. However, the NMR spectra cannot be observed directly, and only the NMR signal, which is a sum of complex exponentials, is directly observable in practice.
Pedro Izquierdo Lehmann +3 more
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On the NMR spectra of pentafluorobenzenes
Journal of Magnetic Resonance (1969), 1969Abstract The AA′BB′C NMR spin systems of the pentafluorobenzene derivatives with the substituents -Cl, -Br, -I, -OH, ⊖-0, -NH 2 , -NH 3 and -CN have been carefully recorded and analyzed completely using in every case iterative fitting to the experimental transitions.
Edward A Cohen +2 more
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