Alkali ion binding to aggregates of amphiphilic compounds studied by nuclear magnetic resonance chemical shifts

1978 ◽  
Vol 100 (15) ◽  
pp. 4647-4654 ◽  
Author(s):  
Hans Gustavsson ◽  
Bjorn Lindman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Ion Binding ◽  
Amphiphilic Compounds ◽  
Nuclear Magnetic ◽  
Alkali Ion

Carbon-13 nuclear magnetic resonance study of potassium and thallium ion binding to the Gramicidin A transmembrane channel

1985 ◽  
Vol 63 (7) ◽  
pp. 1976-1981 ◽  
Author(s):  
D. W. Urry ◽  
T. L. Trapane ◽  
C. M. Venkatachalam ◽  
K. U. Prasad
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Binding Constants ◽  
Potassium Ion ◽  
Gramicidin A ◽  
Ion Concentration ◽  
Ion Binding ◽  
Carbonyl Carbon ◽  
Nuclear Magnetic

By means of carbon-13 nuclear magnetic resonance, carbonyl carbon ion-induced chemical shifts of the Gramicidin A channel are determined at 70 °C and analyzed as a function of potassium ion concentration and as a function of thallium ion concentration. In both cases two binding processes are observed. The estimated binding constants for potassium ion binding are 28/M and 2.4/M for the tight (single ion occupancy) and weak (double ion occupancy) sites, respectively, and for thallium ion binding are of the order of 103/M for the tight site and approximately 70/M for the weak site. These studies, which utilize a 90% enriched carbonyl carbon within the binding site of the channel to monitor ion interaction, argue for the presence of two ions in the channel for conditions under which planar bilayer transport studies are commonly carried out.

Diamagnetic metal ion – nucleoside interactions in solution as studied by 15N nuclear magnetic resonance

1982 ◽  
Vol 60 (6) ◽  
pp. 787-791 ◽  
Author(s):  
G. W. Buchanan ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Metal Ion ◽  
Chemical Shifts ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Physical Measurements ◽  
Highly Sensitive ◽  
Site Selective ◽  
Nuclear Magnetic

15N nuclear magnetic resonance chemical shifts are shown to be highly sensitive to site-selective diamagnetic metal ion binding for the nucleosides adenosine, cytidine, and guanosine. Conclusions regarding preferred complexation sites are compared with results derived from other physical measurements, and with expectations based on electron density calculations.

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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