Nuclear magnetic resonance spectral parameters of α,α,α-trifluorotoluene

1969 ◽  
Vol 47 (18) ◽  
pp. 3313-3318 ◽  
Author(s):  
R. J. Kostelnik ◽  
M. P. Williamson ◽  
D. E. Wisnosky ◽  
S. M. Castellano
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectral Data ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spectral Parameters ◽  
Nuclear Magnetic

The 60 and 100 MHz proton spectra of α,α,α-trifluorotoluene have been recorded and analyzed in terms of chemical shifts and coupling constants. The results of the analyses are compared and the values of the spectral parameters discussed. The nuclear magnetic resonance spectral data of 2-chloro-5-nitro-α,α,α-trifluorotoluene are also reported.

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.

Aqueous solution interaction of the methylmercuric cation with the dinucleotides CpG and dCpdG as studied by carbon-13 nuclear magnetic resonance spectroscopy

1986 ◽  
Vol 64 (10) ◽  
pp. 2038-2041 ◽  
Author(s):  
G. W. Buchanan ◽  
M. J. Bell
Keyword(s):  
Aqueous Solution ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
The Self ◽  
Coupling Constants ◽  
Resonance Spectroscopy ◽  
Spectral Parameters ◽  
Guanine Base ◽  
Nuclear Magnetic

13C nuclear magnetic resonance chemical shifts and 13C–31P coupling constants are reported for the self-complementary dinucleotides CpG and dCpdG in aqueous solution. The influence of methylmercuration at pH 6.0 on these spectral parameters has been examined. Results are interpreted in terms of preferential methylmercuration at the N-7 site of the guanine base of each dinucleotide with concomitant base destacking.

Studies of specifically fluorinated carbohydrates. Part II. Nuclear magnetic resonance studies of pentopyranosyl fluoride derivatives

1969 ◽  
Vol 47 (1) ◽  
pp. 19-30 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Resonance Spectroscopy ◽  
Magnetic Resonance Studies ◽  
Conformational Model ◽  
Nuclear Magnetic

Detailed studies, by 1H and 19F nuclear magnetic resonance spectroscopy, of a series of fully esterified pentopyranosyl fluorides, show that all such derivatives favor that conformer in which the fluorine substituent is axially oriented. This conclusion is supported by separate considerations of the vicinal and geminal19F–1H and 1H–1H coupling constants, of the long-range (4J) 1H–1H and 19F–1H coupling constants and of the 19F chemical shifts. The limitations of the above conformational model are discussed.

scholarly journals Kernresonanz-Untersuchunghen von 1.2.3-Selenadiazolen/ Nuclear Magnetic Resonance of 1,2,3-Selenadiazoles

1981 ◽  
Vol 36 (8) ◽  
pp. 1017-1022 ◽  
Author(s):  
Herbert Meier ◽  
Johannes Zountsas ◽  
Oswald Zimmer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spectroscopical Study ◽  
C Nmr ◽  
Nuclear Magnetic

Abstract A 1H and 13C NMR spectroscopical study is performed on the basis of 37 1,2,3-selena-diazoles. Besides the discussion of chemical shifts and coupling constants of 1H and 13C, selenium satellites were measured providing 1H77 Se and 13C77 Se coupling constants.

PREFERRED RESIDENCE CONFORMATIONS OF DIASTEREOISOMERIC α–β AMINO ALCOHOLS: AN N.M.R. STUDY OF THE EPHEDRINES

1961 ◽  
Vol 39 (12) ◽  
pp. 2536-2542 ◽  
Author(s):  
J. B. Hyne
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Amino Alcohols ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectral results including chemical shifts, anisotropy effects, spin coupling constants, and hydrogen bonding phenomena are presented for the diastereoisomeric pair of α–β amino alcohols (−)-ephedrine and (+)-Ψ-ephedrine. The results are shown to be in keeping with the existence of a preferred residence conformation for each of the diastereoisomers.

scholarly journals Carbon-13 nuclear magnetic resonance spectra of oxazoles

1979 ◽  
Vol 57 (23) ◽  
pp. 3168-3170 ◽  
Author(s):  
Henk Hiemstra ◽  
Hendrik A. Houwing ◽  
Okko Possel ◽  
Albert M. van Leusen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Proton Coupling ◽  
Nuclear Magnetic Resonance Spectra ◽  
C Nmr ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The 13C nmr spectra of oxazole and eight mono- and disubstituted derivatives have been analyzed with regard to the chemical shifts and the various carbon–proton coupling constants of the ring carbons. The data of the parent oxazole are compared with thiazole and 1-methylimidazole.

13C nuclear magnetic resonance spectra of 3,6-disubstituted pyridazines

1991 ◽  
Vol 69 (6) ◽  
pp. 972-977 ◽  
Author(s):  
Gottfried Heinisch ◽  
Wolfgang Holzer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Molecular Orbital Calculations ◽  
Nuclear Magnetic Resonance Spectra ◽  
13C Nuclear Magnetic Resonance ◽  
Magnetic Resonance Spectra ◽  
Nuclear Magnetic

The 13C nuclear magnetic resonance spectra of 17 3,6-disubstituted pyridazine derivatives have been systematically analyzed. Chemical shifts and various 13C, 1H coupling constants are reported. Attempts were made to correlate these data with results obtained from semiempirical molecular orbital calculations as well as with substituent electronegativities and Taft's substituent constants σI and σR0. Key words: 3,6-disubstituted pyridazines, 13C NMR spectroscopy, 13C, 1H spin coupling constants.

Nuclear Magnetic Resonance Studies on Fluorides of Trivalent Phosphorus

1965 ◽  
Vol 20 (2) ◽  
pp. 104-109 ◽  
Author(s):  
G. S. Reddy ◽  
R. Schmutzler
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Trivalent Phosphorus ◽  
Magnetic Resonance Studies ◽  
Regular Change ◽  
Nuclear Magnetic Resonance Spectra ◽  
Multiple Substitution ◽  
Nuclear Magnetic

The P31, F19, and H1 nuclear magnetic resonance spectra of a new series of compounds of the types (RO)nPF3-n and (R2N)nPF3-n (n = 1,2) have been studied. A regular change in the chemical shifts and coupling constants has been observed with multiple substitution. The changes in the coupling constants have been explained on the basis of the electronegativity of the atoms attached to phosphorus. Some long-range coupling constants between hydrogen and fluorine separated by five bonds were observed.

Sign in / Sign up

Export Citation Format

Share Document