scholarly journals Toward the quantum chemical calculation of nuclear magnetic resonance chemical shifts of proteins

2011 ◽  
Vol 79 (7) ◽  
pp. 2189-2202 ◽  
Author(s):  
Andrea Frank ◽  
Ionut Onila ◽  
Heiko M. Möller ◽  
Thomas E. Exner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quantum Chemical Calculation ◽  
Quantum Chemical ◽  
Chemical Shifts ◽  
Chemical Calculation ◽  
Nuclear Magnetic

scholarly journals Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives

2018 ◽  
Vol 5 (6) ◽  
pp. 180088 ◽  
Author(s):  
M. Petrova ◽  
R. Muhamadejev ◽  
B. Vigante ◽  
G. Duburs ◽  
Edvards Liepinsh
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Hydrogen Bonds ◽  
Quantum Chemical ◽  
Variable Temperature ◽  
Chemical Calculation ◽  
Hydrogen Bond Formation ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen ◽  
Nuclear Magnetic

1,4-Dihydropyridine (1,4-DHP) derivatives have been synthesized and characterized by 1 H, 13 C, 15 N nuclear magnetic resonance (NMR) spectroscopy, secondary proton/deuterium 13 C isotope shifts, variable temperature 1 H NMR experiments and quantum-chemical calculation. The intramolecular hydrogen bonds NH⋯O=C and CH⋯O=C in these compounds were established by NMR and quantum-chemical studies The downfield shift of the NH proton , accompanied by the upfield shift of the 15 N nuclear magnetic resonance signals, the shift to the higher wavenumbers of the NH stretching vibration in the infrared spectra and the increase of the 1 J( 15 N, 1 H) values may indicate the shortening of the N–H bond length upon intramolecular NH⋯O=C hydrogen bond formation.

Carbon-13 nuclear magnetic resonance examination of naphthalene derivatives. Assignments and analysis of substituent chemical shifts

1977 ◽  
Vol 42 (14) ◽  
pp. 2411-2418 ◽  
Author(s):  
William Kitching ◽  
Maxwell Bullpitt ◽  
David Gartshore ◽  
William Adcock ◽  
T. C. Khor ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Magnetic Resonance Examination ◽  
Naphthalene Derivatives ◽  
Nuclear Magnetic

Nuclear Magnetic Resonance Chemical Shifts of some Monosubstituted Isothiazoles

1975 ◽  
Vol 53 (4) ◽  
pp. 596-603 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Thomas R. Clem ◽  
Edwin D. Becker
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Charge Densities ◽  
Monosubstituted Benzenes ◽  
Proton Chemical Shifts ◽  
Nuclear Magnetic

Carbon-13 and proton chemical shifts have been measured for several monosubstituted isothiazoles. Substituent effects upon these chemical shifts are compared with those observed for monosubstituted benzenes, pyridines, and thiophenes. In general the observed substituent effects in the isothiazoles and thiophenes closely parallel one another. Correlations between the observed carbon-13 Chemical shifts and CNDO/2 calculated charge densities are examined.

Studies of specifically fluorinated carbohydrates. Part I. Nuclear magnetic resonance studies of hexopyranosyl fluoride derivatives

1969 ◽  
Vol 47 (1) ◽  
pp. 1-17 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville ◽  
N. S. Bhacca
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Angular Dependence ◽  
Chemical Shifts ◽  
Relative Orientation ◽  
Coupling Constants ◽  
Pyranose Ring ◽  
Spectral Parameters ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

A detailed study has been made of both the 1H and 19F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl fluoride derivatives. Some of the 1H spectra were measured at 220 MHz. The 1H spectral parameters define both the configuration and the conformation of each of these derivatives. Study of the 19F n.m.r. parameters revealed several stereospecific dependencies. The 19F chemical shifts depend upon, (a) the orientation of the fluorine substituent with respect to the pyranose ring and, (b) the relative orientation of other substituents attached to the ring; for acetoxy substituents, these configurational dependencies appear to be additive. The vicinal19F–1H coupling constants exhibit a marked angular dependence for which Jtrans = ca. 24 Hz whilst Jgauche = 1.0 to 1.5 Hz for [Formula: see text] and 7.5 to 12.6 Hz for [Formula: see text] The geminal19F–1H couplings depend on the orientation of the substituent at C-2; when this substituent is equatorial JF,H is ca. 53.5 Hz and when it is axial the value is ca. 49 Hz.

The metal nuclear magnetic resonance spectra of some tin(II) and lead(II) complexes with polydentate phosphines

1983 ◽  
Vol 61 (8) ◽  
pp. 1795-1799 ◽  
Author(s):  
Philip A. W. Dean
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Narrow Range ◽  
Chemical Shifts ◽  
Nuclear Magnetic Resonance Spectra ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The previously reported 1:1 complexes formed in MeNO2, between M(SbF6)2 (M = Sn or Pb) and Ph2P(CH2)2PPh2, PhP[(CH2)2PPh2]2, MeC(CH2PPh2)3, P[(CH2)2PPh2]3, and [Formula: see text] have been studied by metal (119Sn or 207Pb) nmr. The metal chemical shifts span the comparatively narrow range of −586 to −792 ppm and 60 to −269 ppm, relative to the resonance of MMe4, for 119Sn and 207Pb nmr, respectively. The implications of these data regarding the denticity of the ligand in M(P[(CH2)2PPh2]3)2+ are discussed, and a comparison with the metal nmr spectra of related stannous and plumbous complexes is made.

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