Temperature dependence of the 59Co quadrupole coupling constant in K3Co(CN)6

1980 ◽  
Vol 58 (1) ◽  
pp. 68-73 ◽  
Author(s):  
J. A. J. Lourens ◽  
E. Smit
Keyword(s):  
Temperature Dependence ◽  
Structural Phase ◽  
Intermediate Frequency ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Positive Contribution ◽  
Coupling Constant ◽  
Quadrupole Coupling ◽  
Bond Stretching ◽  
Modes Of Vibration

Expressions are presented for calculating the effects of bond-stretching and rotational modes of vibration on the temperature dependence of quadrupole coupling constants in crystals. Contributions to the motional averaging of the electric field gradient tensor arising from point charges, point dipoles, and overlap of closed wave functions are evaluated and the resulting expressions applied to analyse the temperature variation of the 59Co quadrupole coupling constant in K3Co(CN)6. Both stretching and rotational internal modes of vibration of the Co(CN)6 octahedron had to be taken into account to analyse the data. In particular, an intermediate frequency mode of wavenumber 414 cm−1 has been found to make a substantial and positive contribution to the shift in coupling constant arising from the low (~ 100 cm−1) and intermediate frequency (~ 400 cm−1) modes. The remainder of the shift (~ 90%) has been attributed to a rotary mode of wavenumber 26 cm−1. The extracted temperature dependence of this mode points to the possible existence of a structural phase transition in K3Co(CN)6 below 100 K.

Dissecting the Effects of Water Guest Adsorption and Framework Breathing on the AlO4(OH)2 Centers of Metal-Organic Framework MIL-53 (Al) by Solid State NMR and Structural Analysis

2021 ◽  
Author(s):  
Alexander G. Stepanov ◽  
Alexander E. Khudozhitkov ◽  
Sergei S. Arzumanov ◽  
Alexander V. Toktarev ◽  
Svetlana Cherepanova ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Metal Organic Framework ◽  
Structural Phase ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Aluminium Atom ◽  
Quadrupole Coupling ◽  
Adsorption Of Water ◽  
Metal Organic ◽  
The Relationship

The relationship between the adsorption of water on MIL-53 (Al) MOF, the structural phase of MIL-53 (Al), and quadrupole coupling constant of 27Al framework aluminium atom (QCC) of the MOF...

Weak Complexes of Dinitrogen: An Approach to the 14N-Nuclear Quadrupole Coupling Constant of Free N2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 367-370 ◽  
Author(s):  
A. C. Legon ◽  
P. W. Fowler
Keyword(s):  
Ground States ◽  
Zero Point ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Nuclear Quadrupole Coupling Constant ◽  
Quadrupole Coupling ◽  
Weak Complexes ◽  
Nuclear Quadrupole

AbstractThe 14N-nuclear quadrupole coupling constants χaa(14N<2>) and χaa(14N(1)) for the ground-states of the dimers 14N(2)14N(1) • • • HCCH and 14N(2)14N(1) • • • HC15N have been corrected for zero-point effects and for the electrical effects of the subunit HX to give two estimatesχ(14N) = -5.01 (13) and - 5.07 (8) MHz, respectively, for the coupling constant of the isolated 14N2 molecule

A boroxol ring doped zigzag boron nitride nanotube: a computational DFT study of the quadrupole coupling constant

2009 ◽  
Vol 87 (6) ◽  
pp. 647-652 ◽  
Author(s):  
Asadollah Boshra ◽  
Ahmad Seif
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Density Functional ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Boron Nitride Nanotube ◽  
Coupling Constant ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Dopant Atoms

Based upon density functional theory, we investigate the influence of oxygen dopant atoms that make a boroxol ring on the electrostatic properties of a zigzag (10, 0) boron nitride nanotube in which three of the nitrogen atoms are replaced by oxygen dopant atoms. The electric field gradient (EFG) tensors at the sites of 11B and 14N nuclei were calculated and converted to quadrupole coupling constants (CQ) in the two models of a perfect and a boroxol ring O-doped (10, 0) single-walled boron nitride nanotube (BNNT). Our calculations showed that the CQ values of the boron and nitrogen nuclei along the length of a perfect BNNT are divided into layers. Among the layers the mouth layers have the largest CQ magnitudes. In the doped model, in addition to the mouth layers, the CQ values of those nitrogen nuclei which directly bond to the boroxol ring are increased. However, the CQ values of the boron nuclei that make the boroxol ring and directly bond to the boroxol ring are decreased.

scholarly journals Notizen:Hyperfeinstruktur von CsCl

1972 ◽  
Vol 27 (10) ◽  
pp. 1516-1517
Author(s):  
J. Hoeft ◽  
E. Tiemann ◽  
T. Törring
Keyword(s):  
Hyperfine Structure ◽  
Line Width ◽  
Quadrupole Coupling Constant ◽  
Rotational Transition ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Vibrational States ◽  
Upper Limit ◽  
Quadrupole Coupling ◽  
Rotational Transitions

Abstract The quadrupole hyperfine structure of 133Cs35Cl was measured on the rotational transition J=1 → 2 at 8.6 GHz. The calculated quadrupole coupling constants of 35Cl in various vibrational states are reported. The observed line width of the rotational transitions yields an upper limit of the quadrupole coupling constant of 133Cs.

35Cl AND 37Cl MAGNETIC RESONANCE OF SIMPLE CHLORINE COMPOUNDS

1965 ◽  
Vol 43 (9) ◽  
pp. 2530-2534 ◽  
Author(s):  
Yasukazu Saito
Keyword(s):  
Chemical Shift ◽  
Chemical Shifts ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Reference Compound ◽  
Excitation Energies ◽  
Structural Applications ◽  
Quadrupole Coupling ◽  
Magnetic Resonances

The nuclear magnetic resonances of 35Cl and 37Cl in a number of simple chlorine compounds were measured. Since both the paramagnetic contribution for chemical shift and the quadrupole coupling constant of the atom are determined by the same radial distribution of the electron, a linear relationship between the chemical shifts and the quadrupole coupling constants may be expected for compounds for which the electronic excitation energies are comparable. This was demonstrated for the series of chloro-substituted methanes. By graphical extrapolation the absolute chemical shift of the reference compound, NaCl aqueous solution, was obtained. The chemical shift of Cl− aq. ion can be interpreted as the sum of the diamagnetic shift of Cl− spherical ion and a paramagnetic shift resulting from its hydration. The experimental and theoretical values of the paramagnetic chemical shift of the Cl2 molecule were −2.06 × 10−3 and −2.17 × 10−3, respectively. Paramagnetic chemical shifts and line widths of resonance spectra of simple chlorine compounds are discussed, as well as the feasibility of high-resolution chlorine resonances for structural applications.

The Temperature Dependence of 121,123Sb, 35Cl, 79,81Br and 127I NQR Spectra in Complexes Cs3Sb2X9 (X = Cl, Br, I)

2000 ◽  
Vol 55 (1-2) ◽  
pp. 134-138 ◽  
Author(s):  
L. A. Zemnukhova ◽  
S. I. Kuznetsov ◽  
G. A. Fedorishcheva ◽  
R. L. Davidovich
Keyword(s):  
Electric Field ◽  
Aqueous Solutions ◽  
Electric Field Gradient ◽  
Temperature Dependence ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Quadrupole Transition ◽  
Quadrupole Coupling ◽  
Coeffi Cients ◽  
Constant E

The 123,123Sb, 35Cl, 79,81Br and 127I NQR Spectra of the complexes Cs3Sb2X9 (X = Cl, Br, I), prepared from CsX and SbX3 aqueous solutions, were studied at 77-400 K. Analysis of the^ temperature coeffi-cients of the quadrupole transition frequency (v), quadrupole coupling constant (e2Qqzz) and asymme-try parameter of the electric field gradient (η) was carried out.

TEMPERATURE DEPENDENCE OF THE PURE NUCLEAR QUADRUPOLE RESONANCE FREQUENCY IN KClO3

1960 ◽  
Vol 38 (11) ◽  
pp. 1397-1405 ◽  
Author(s):  
J. Vanier
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Quadrupole Coupling Constant ◽  
Nuclear Quadrupole Resonance Frequency ◽  
Lattice Vibrations ◽  
Coupling Constant ◽  
Air Temperatures ◽  
Quadrupole Coupling ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole

The resonant frequency of the Cl35 nuclear quadrupole in KClO3 has been measured as a function of temperature in the range 15 deg;K to 77 deg;K; previous work between 77 deg;K and room temperature has been confirmed. Comparison has been made with Bayer's theory based on lattice vibrations and agreement is excellent. The ratio of the quadrupole coupling constant eQqzz of the two isotopes (Cl35 and CI37) has been measured at room and liquid air temperatures; significant changes have been observed in the measurements. Finally the possibility of using this temperature dependence as the basis of a sensitive thermometer has been studied; the accuracy of such a thermometer would be ±0.005 deg;K at 60 deg;K and ±0.05 deg;K at 20 deg;K.

Theory of Nuclear Quadrupole Interactions in Solid Fluoromethanes with Implanted 19F* Nuclei. Coupling of HF* and Host Molecule

1996 ◽  
Vol 51 (5-6) ◽  
pp. 565-571
Author(s):  
G. Gowri ◽  
Tina Briere ◽  
Sudha Srinivas ◽  
Hwa-Suck Cho ◽  
T.P. Das ◽  
...  
Keyword(s):  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Molecular Systems ◽  
Hartree Fock ◽  
Nuclear Quadrupole Interactions ◽  
Field Gradients ◽  
Quadrupole Coupling ◽  
Constant E ◽  
Total Energies

Abstract The Quadrupole Coupling Constant e2qQ and Asymmetry Parameter η of fluorine for fluorine-substitute methane compounds are calculated using the Hartree-Fock Roothaan procedure. Our results are compared with experimental data from measurements by the Time Differential Perturbed Angular Distribution (TDPAD) technique using excited 19F* (spin 5/2) nuclei. The theoretical e2qQ’s for the 19F* nuclei in the fluoromethanes are in good agreement with experimental results. For CH2F2 and CHClF2 molecules, where finite η are expected from symmetry considerations, our results for η are small, 0.12 and 0.05 respectively, in agreement with experimental observation. Besides the 19F* coupling constants associated with the C-F bonds in fluoromethanes, additional interesting NQI parameters, close to those in solid hydrogen fluoride, are observed in the TDPAD measurements. It is demonstrated through investigations of the total energies and electric field gradients that these additional NQI parameters for the fluoromethanes can be explained by a HF* molecule hydrogen-bonded through the hydrogen to a fluorine atom in the host molecular systems. This complexing of an ionic molecule to the host molecules in organic solids containing strongly electronegative atoms is expected to be a general feature in both implantation and conventional techniques.

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