Showing papers in "Journal of Magnetic Resonance in 1975"

TL;DR: In this article, the shape function, normalized by integration over the magnetic field, must be multiplied by a factor which in the S = 12 case equals the inverse of the g-value.

TL;DR: In this article, the effect of the magnetic dipolar interaction of a nuclear spin with the thermal average of an electronic spin (Curie spin) is modulated by molecular motion but not by the electronic spin relaxation.

TL;DR: The experimental requirements for pulse FT NMR measurements of spin-lattice relaxation times (T 1's) are quite demanding as discussed by the authors, and variables such as sample geometry and state, transmitter rf pulse power, computer and data processing characteristics, and instrumental gain stability and magnetic field homogeneity must all be optimized or closely controlled in order to obtain accurate data.

TL;DR: In this paper, 12 trimethylsilyl compounds have been studied by 29 Si and 13 C NMR data for chemical shifts, coupling constants, and spin-lattice relaxation times are reported.

TL;DR: In this article, a general study of the mercury-199 Fourier transform nuclear magnetic resonance has been completed, in which 25 millimolar solutions of isotopically normal mercury in HgCl2 exhibited a resonance with a root mean-square signal-to-noise ratio of 9.1 in 10.2 hours.

TL;DR: In this article, a method has been devised whereby the uniform field linear electric field shift (LEFS) contribution to the total titration shift may be isolated, and it is shown that if the titration shifts can be analysed into their component contributions, it is possible to estimate the magnitudes of the electric field at each carbon and the changes in electron density on each carbon induced by protonation.

TL;DR: In this article, it is shown that by considering the 13 C ρ 1 H coupling constants between the α-CO 2 − and the β-protons, it is possible to obtain side-chain conformational information concerning the rotamer populations which is not available from studies of H ρ coupling constants alone.

TL;DR: In this paper, two chemically shifted resonances, separated by ∼015 ppm, arise from phosphate groups in phospholipid molecules on the inside and the outside of the spherical bilayer vesicles.

TL;DR: In this paper, the 1H NMR parameters for the 20 common amino acid residues have been measured in the protected linear peptides TFA-Gly(1)-Gly (2)- l -X(3), l -Ala(4)OCH3 in d6-DSMO solution.

TL;DR: In this paper, the 13 C NMR spectra of a variety of isonitrile complexes have been studied and a metal triad shielding trend is observed with the isoniitrile complex as has been found previously in carbonyl-, carbene-, and alkylmetal compounds.

TL;DR: In this article, phase modulation of the decoupler carrier frequency with a 50% duty cycle square wave is shown to be an efficient method for broad-band decoupling.

TL;DR: In this paper, high-resolution proton coupled and single-frequency proton decoupled 13 C FT NMR spectra of 15 N-enriched pyrrole have been recorded.

TL;DR: Using nuclear double resonance techniques, the nuclear quadrupole resonance of deuterium in both HDO and D2O molecules in isotopically enriched hexagonal ice at 77 K has been measured.

TL;DR: In this article, the authors derived the tensor angular correlation of the vicinal 13C′NCα1H and 1HCαC′N coupling constants from experimental data, where the first coupling is a function of the φ torsional angle of the peptide backbone.

TL;DR: The second-order perturbation energy of a spin Hamiltonian, valid for low symmetry and an arbitrary number of nuclei, is reported and discussed in this article, where the nuclear Zeeman terms, as well as certain cross terms missing in previous publications, have been included.

TL;DR: In this paper, the signs and magnitudes of all possible 13 C-1H coupling constants in toluene as well as 1H chemical shift differences, including long-range 13 C isotope shifts, could be determined from the analysis of these complex spectra.

TL;DR: In this paper, the response of a system of nuclear spins I = 3 2 experiencing electric quadrupole couplings in zero externally applied field to two pulse sequences is examined using time-dependent perturbation theory.

TL;DR: In this paper, a model is proposed to explain the additional minima and nonexponentiality of the proton Zeeman spin-lattice relaxation at low temperatures in certain samples containing tetrahedral four proton groups.

TL;DR: In this article, the deuterium isotope effects on the 13C chemical shifts of several amino acids and dipeptides have been measured, and the dependency of the isotope shift upon the number of deuterons attached to the nitrogen and the distance of the carbon in question from a deuterated site suggest a method for assignments in complicated systems such as polypeptide and proteins.

TL;DR: In this paper, a method for the calculation of the correlation functions and their Fourier spectra governing the relaxation times TI, T 2 and T 1 ϱ in the high-field limit is presented.

TL;DR: In this paper, the quadrupole moment ratio 97Q95Q = 11.4 ± 0.4 was obtained for aqueous solutions of sodium molybdate in the pH range 7-12.

TL;DR: In this paper, the authors reported dipole-dipole and nuclear quadrupole splittings for tetrahedral ions NH4+, ND4+ and BF4− in lyotropic liquid crystal phases.

TL;DR: This paper presents a broad class of methods which not only do not require any interpretation of experimental lines but do not even require that any lines should be individually distinguishable, leading to quite optimistic conclusions regarding the possibility of full automation of the problem in question.