Experimental Study of Nuclear Electric Quadrupole Splittings of 59Co in Co(NH3)6Cl3

1974 ◽  
Vol 52 (15) ◽  
pp. 1398-1404 ◽  
Author(s):  
E. C. Reynhardt
Keyword(s):  
Experimental Study ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Electric Field Gradient ◽  
Room Temperature ◽  
Electric Quadrupole ◽  
Coupling Constants ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Asymmetry Parameters

The nuclear magnetic resonance of 59Co in a single crystal of Co(NH3)6Cl3 has been investigated at room temperature at 15 kG. Observed quadrupolar perturbations have been analyzed by the method of Volkoff for three orthogonal planes to yield five electric field gradient tensors. The cobalt sites associated with these tensors are nonequivalent. The quadrupole coupling constants and asymmetry parameters vary from 1.0 to 17.2 MHz and 0.10 to 0.57 respectively. One of the principal axes of each tensor is found to coincide with the crystallographic b axis of the monoclinic unit cell.

scholarly journals Hydrogen Bond Studies. 125. A Deuteron Magnetic Resonance Study of Strontium Formate Dihydrate, Sr(HCOO)2 · 2D2O

1977 ◽  
Vol 32 (9) ◽  
pp. 1025-1029 ◽  
Author(s):  
Bo Berglund ◽  
Jörgen Tegenfeldt
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Magnetic Resonance ◽  
Electric Field Gradient ◽  
Room Temperature ◽  
Coupling Constants ◽  
Water Molecules ◽  
Magnetic Resonance Study ◽  
Quadrupole Coupling ◽  
Asymmetry Parameters

AbstractA room temperature (25 °C) deuteron magnetic resonance (DMR) study of a single crystal of Sr (HCOO)2 · 2 D2O is reported. Signals from all water molecules in the unit cell have been detected, and all four independent electric field gradient (EFG) tensors at the water deuterons have been determined from 409 quadrupole splittings. All spectra were recorded by rotating the crystal about one arbitrarily selected axis. The following quadrupole coupling constants and asymmetry parameters for the deuterons were obtained: 213.5(4), 189.3(4), 195.7(4) and 200.7(5) kHz and 0.117(3), 0.110(4), 0.116(4) and 0.098(3). The directions of the eigenvalues are qualitatively consistent with the crystal structure refined by Galigné 1; the result is in disagreement, however, with the earlier DMR study of Sr (DCOO)2 · 2 D2O (Reference 2).

Quadrupoleffekte der magnetischen Kernresonanz an 11B in Bor-Stickstoffverbindungen

1969 ◽  
Vol 24 (4) ◽  
pp. 566-572 ◽  
Author(s):  
Klaus Wiedemann ◽  
Jürgen Voitländer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Quadrupole Interaction ◽  
Second Order ◽  
Coupling Constants ◽  
Quadrupole Coupling ◽  
Wide Line ◽  
Nuclear Quadrupole ◽  
Asymmetry Parameters ◽  
Nuclear Magnetic

Abstract First and second-order quadrupole effects of the 11B nuclear magnetic resonance have been measured in polycrystalline samples of dimere dimethylaminoboranes and tetramethylboracene. With the theory of powder patterns for first and second-order quadrupole interaction the nuclear quadrupole coupling constants e2 q Q/h and asymmetry parameters η of 11B have been determined. For these measurements boron-free inserts had to be constructed for the probes of the Varian Wide Line Spectrometer DA 60.

14N and 39K Nuclear Quadrupole Coupüng in KNO3

1990 ◽  
Vol 45 (3-4) ◽  
pp. 459-463 ◽  
Author(s):  
T. J. Bastow ◽  
S. N. Stuart
Keyword(s):  
Phase Transition ◽  
Nuclear Magnetic Resonance ◽  
Room Temperature ◽  
Potassium Nitrate ◽  
Nuclear Quadrupole Interaction ◽  
Coupling Constants ◽  
Disorder Phase Transition ◽  
Nuclear Quadrupole ◽  
T Values ◽  
Asymmetry Parameters

Abstract The nuclear quadrupole interaction tensors of 14N and 39K in potassium nitrate at room temperature have been determined from nuclear magnetic resonance (NMR) rotation studies of single crystals at 9.4 T. Values for the coupling constants and asymmetry parameters at 296 K are:14N: e2 qQ/h = 751 kHz, η = 0.022; 39K: e2 qQ/h = 1326kHz, η = 0.171. The temperature dependence, on approaching the order-disorder phase transition near 401 K, is linear.

NUCLEAR ELECTRIC QUADRUPOLE INTERACTION IN SINGLE CRYSTALS

1952 ◽  
Vol 30 (3) ◽  
pp. 270-289 ◽  
Author(s):  
G. M. Volkoff ◽  
H. E. Petch ◽  
D. W. L. Smellie
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Electric Quadrupole ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Gradient Tensor ◽  
Absolute Value ◽  
Principal Axes ◽  
Quadrupole Coupling

Pound's theory of the dependence of electric quadrupole splitting of nuclear magnetic resonance absorption lines in a single crystal on the orientation of the crystal in an external magnetic field is extended to cover the case of a crystal with nonaxially symmetric electric field gradient at the site of the nuclei being investigated. It is shown that an experimental study of the angular dependence of this splitting for three independent rotations of the crystal about any three mutually perpendicular axes will yield complete information about the orientation of the principal axes and the degree of axial asymmetry of the electric field gradient tensor at the site of the nuclei, and also will give the absolute value of the quadrupole coupling constant for those nuclei.The authors' experiments on the splitting of the Li7 absorption lines in a single crystal of LiAl(SiO3)2 (spodumene) are described and are used to illustrate the theory. The absolute value of the quadrupole coupling constant for the Li7 nuclei in spodumene is found to be [Formula: see text]. per sec. The axial asymmetry parameter of the field gradient tensor at the site of the Li nuclei is found to be η≡(ϕxx−ϕvv)ϕzz=0.79 ± 0.01. One of the principal axes of this tensor (the y axis corresponding to the eigenvalue of intermediate magnitude) is experimentally found to coincide with the b crystallographic axis of monoclinic spodumene as required by the known symmetry of the crystal. The other two principal axes are in the ac plane, the z axis (corresponding to the eigenvalue ϕzz of greatest magnitude) lying between the a and c axes at an angle of 48° ± 2° with the c axis.

The Electric Field Gradient at the Site of the Halogen Ion and Structure of Amino Acid Hydrobromides and Hydroiodides

1992 ◽  
Vol 47 (7-8) ◽  
pp. 887-917
Author(s):  
Armin Kehrer ◽  
Shi-qi Dou ◽  
Alarieh Weiss
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Room Temperature ◽  
Low Frequency ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Resonance Frequencies ◽  
Quadrupole Coupling ◽  
Frequency Coupling

Abstract The 79,81Br and 127I NQR spectra of several hydrobromides, respectively hydroiodides, of amino acides and dipeptides were studied, mostly as functions of temperature in the range 77 < T/K <420. The investigated compounds are: L-Arg • HBr • H2O, L-Cys • HBr • H2O , L - Cys - S - S - L - Cys • 2HBr, ethanolamine • HBr, L-Glu • HBr, L-His • HBr, L-His • 2HBr, L-Ile HBr • H2O , Sar • HBr, (Sar)2 • HBr, L-Val • HBr • H2O , Gly • LiBr, Gly-Gly • LiBr, ethanolamine HI, Sar • HI, (Sar)2 • HI, (Gly)2 • HI, (L-Val)2 • HI, Gly-L-Leu • HI • H2O . A phase transition with hysteresis was observed for L-Val • HBr • H2O (Tc.up = 318 K, Tc.down = 242 K). Two solid phases of Sar • HI have been studied by NQR, one crystallized from melt, the other one from aqueous solution. For three of the title compounds the crystal structure was determined at room temperature: L-His - 2HBr, P212121 , Z = 4, aj pm = 1652, b/pm = 916, c/pm = 721; L-Cys HBr H2O , P212121 , Z = 4, a/pm = 1955, b/pm = 746, c/pm = 550; Gly-L-Leu • HI • H2O , P2X, Z = 2, a / p m = 1289, b/pm = 914, c/pm = 615, ß/° = 99.In most cases the halogen ion in the studied hydrohalides is polycoordinated by hydrogen bonds of the type N - H • • • X⊖ and O - H • • • X⊖ , X = Br, I. The NQR frequencies and, for iodine, the nuclear quadrupole coupling constants depend on this coordination. A low frequency (coupling constant) region is found for pure N - H • • • X⊖ coordination. Replacing one N - H • • • X⊖ bond by O - H • • • X⊖ rises the electric field gradient, EFG, respectively the resonance frequencies. The dependence of the EFG on the hydrogen bond coordination N - H • • • X⊖ plus O - H • • • X⊖ is discussed for the title compounds including information from literature

Electric Field Nuclear Magnetic Resonance (Application to Nuclear Quadrupole Coupling)

1986 ◽  
Vol 41 (1-2) ◽  
pp. 421-424 ◽  
Author(s):  
B. H. Ruessink ◽  
C. MacLean
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Electric Field ◽  
Experimental Method ◽  
Theoretical Approach ◽  
Liquid State ◽  
Experimental Results ◽  
Coupling Constants ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

The technique of electric field NMR is outlined in terms of theoretical approach and of experimental method. As an illustration, new and recent values for quadrupole coupling constants measured in the liquid state are reported. They are compiled together with observations from the solid and the gas. A discussion concerning the differences between the phases is briefly given. Experimental results of quadrupole coupling constants for all of the three phases are still scarce.

NUCLEAR MAGNETIC RESONANCE SPECTRUM OF B11 IN KERNITE

1955 ◽  
Vol 33 (5) ◽  
pp. 156-175 ◽  
Author(s):  
H. H. Waterman ◽  
G. M. Volkoff
Keyword(s):  
Magnetic Field ◽  
Coupling Constants ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Radio Frequency Spectrum ◽  
Asymmetry Parameters ◽  
Crystallographic Axes ◽  
The Magnetic Field

The radio-frequency spectrum of B11 in a single crystal of Na2B4O7∙4H2O (kernite) is examined experimentally as the monoclinic crystal is rotated in an external magnetic field of 7060 gauss in turn about each of three axes (b, c crystallographic axes, and a third perpendicular direction) held normal to the magnetic field. A maximum of 21 lines (some of which show small additional splitting) is observed, which reduces to 11 when the b symmetry axis is perpendicular or parallel to the magnetic field. The results are interpreted in terms of four essentially non-equivalent B11 sites in kernite characterized respectively by quadrupole coupling constants [Formula: see text], 0.588 ± 0.003, 2.563 ± 0.007, 2.567 ± 0.010 Mc./sec, and asymmetry parameters 77 [Formula: see text], 0.60 ± 0.02, 0.163 ± 0.010, 0.116 ± 0.010. The orientations of the principal axes of the four [Formula: see text] tensors are also determined. These observations on boron are consistent with previous X-ray results, but preliminary observations on Na23 in kernite contradict previous X-ray position assignments.

Sign in / Sign up

Export Citation Format

Share Document