scholarly journals Proton Magnetic Resonance Spectrum of 2-Chloroaniline-15N. Long-range Coupling Constants to Amino Protons from all Ring Protons

1971 ◽  
Vol 49 (22) ◽  
pp. 3627-3635 ◽  
Author(s):  
R. Wasylishen ◽  
T. Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Proton Exchange ◽  
Coupling Constants ◽  
Amino Group ◽  
Fast Rotation ◽  
The One

The p.m.r. spectra of 2-chloroaniline and 2-chloroaniline-15N in benzene and toluene solutions are analyzed at 60 and 100 MHz under conditions where the amino protons are exchanging intermolecularly and also where they are not exchanging. The spectrum of 2-chloroaniline-H15ND in the absence of amino proton exchange is observed between −48 and 80 °C. In all situations fast rotation about the C—N bond evidently occurs. Long-range couplings of the amino protons to all ring protons are observed and their signs are determined. The nonplanarity of the amino group is discussed in terms of the long-range couplings, of the one-bond 15N–H couplings, and of the two-bond H–H couplings in the amino group. The signs and magnitudes of the coupling constants between the ring protons and 15N are also determined.

Conformational dependence of long-range spin-spin coupling constants in 2,6-dichlorobenzylfluoride

1969 ◽  
Vol 47 (19) ◽  
pp. 3688-3690 ◽  
Author(s):  
T. Schaefer ◽  
C. M. Wong ◽  
K. C. Tam
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Double Resonance ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

Double resonance experiments on the proton magnetic resonance spectrum of 2,6-dichlorobenzylfluoride yield the signs of the long-range coupling constants between the ring protons and the fluorine nuclei and protons in the fluoromethyl group. The signs and magnitudes of the long-range couplings are discussed in terms of their dependence on the conformation of the fluoromethyl group.

The Proton Magnetic Resonance Spectrum of p-Methylbenzylbromide, Conformational Preference of the Bromomethyl Rotor

1974 ◽  
Vol 52 (20) ◽  
pp. 3489-3494 ◽  
Author(s):  
Kalvin Chum ◽  
J. Brian Rowbotham ◽  
Ted Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Alternative Model ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constants ◽  
The Other ◽  
Complete Analysis ◽  
Conformational Preference

A complete analysis is given of the nine-spinproton magnetic resonance spectrum of p-methylbenzyl bromide as a 20 mol% solution in acetone-d6 The long-range coupling constants between methyl and ring protons are the same as those in toluene. The coupling constants between the methylene protons and the other protons in the molecule are consistent with a two-fold barrier of 500 ± 200 cal/mol for the bromomethyl group, the preferred conformation having the C—Br bond in a plane perpendicular to the aromatic plane. An alternative model, in which a C—H bond of the bromomethyl rotor prefers the aromatic plane to the extent of 3 kcal/mol, is considered unlikely.

Das Protonenresonanzspektrum von orientiertem Benzol in nematisch-kristallinflüssiger Lösung

1965 ◽  
Vol 20 (4) ◽  
pp. 572-580 ◽  
Author(s):  
Alfred Saupe
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constants ◽  
Scalar Coupling ◽  
Small Temperature ◽  
Theoretical Methods ◽  
Experimental Errors

The proton magnetic resonance spectrum of benzene oriented in a nematic solution is calculated using group theoretical methods. The calculations agree within experimental errors with the spectrum of benzene observed in a nematic solution of 4.4′-di-n-hexyloxy-azoxy-benzene. By an improvement of the temperature homogenity in the sample it was possible to obtain linewidths of only about 5 cps for all lines independent of the splitting. It is confirmed that the signs of the scalar coupling constants between ortho and meta protonpairs are positive. A small temperature dependence of the chemical shift of the benzene protons was found in the nematic solution. It is due to the dependence of the average orientation on the temperature.

Proton magnetic resonance spectrum of 2,6-dichlorobenzaldoxime. Signs and magnitudes of long-range spin–spin couplings. Degree of nonplanarity

1969 ◽  
Vol 47 (19) ◽  
pp. 3707-3709
Author(s):  
T. Schaefer ◽  
R. Wasylishen
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum ◽  
Coupling Constant ◽  
Hydroxyl Proton ◽  
Ring Proton ◽  
Proton Shift

From the sign and magnitude of the coupling constant between the C—H proton in the sidechain and the para ring proton in 2,6-dichlorobenzaldoxime it is estimated that the deviation from coplanarity of the sidechain is at least 40°. The hydroxyl proton shift in dimethylsulfoxide solution of −11.7 p.p.m., relative to internal tetramethylsilane, indicates a cis arrangement of the hydroxyl and aromatic groups.

1H nuclear magnetic resonance study of 2,2′-anhydro-O2-β-D-arabinosyluracil. Four- and five-bond coupling constants in the sugar moiety

1979 ◽  
Vol 57 (16) ◽  
pp. 2191-2195 ◽  
Author(s):  
Frank E. Hruska ◽  
James G. Dalton ◽  
Mieczyslaw Remin
Keyword(s):  
Magnetic Resonance ◽  
Long Range ◽  
Resonance Spectrum ◽  
Double Resonance ◽  
Proton Magnetic Resonance Spectrum ◽  
Nuclear Magnetic Resonance Study ◽  
Anomeric Proton ◽  
Coupling Constants ◽  
Magnetic Resonance Study ◽  
1H Nuclear Magnetic Resonance

A high resolution proton magnetic resonance spectrum for 2,2′-anhydro-O2-β-D-arabinosyluracil in aqueous solution at 80 °C is presented. The spectrum provides evidence for the presence of long-range four-bond (4J1′3′, 4J1′4′, 4J2′4′) and five-bond (5J1′5′, 5J1′5′′, 5J2′5′, 5J2′5′′) coupling interactions involving the furanose hydrogens. The 5J data represent the first reported evidence for the presence of coupling interactions involving the anomeric proton and exocyclic C5′ protons in a furanose system. The relative signs of the 4J and 5J couplings were determined by double resonance methods. The 4J and 5J interactions are discussed using crystallographic data and the theory of long-range couplings.

Proton magnetic resonance spectrum of 4-pyrone, chromone and xanthone

1966 ◽  
Vol 22 (7) ◽  
pp. 1391
Author(s):  
Caroline T. Mathis ◽  
J.H. Goldstein
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Resonance Spectrum ◽  
Proton Magnetic Resonance Spectrum
Sign in / Sign up

Export Citation Format

Share Document