Static and Dynamic Structures of InBrx (x = 1.4, 1.5, 1.75, and 2) Studied by 81Br NQR and 115In NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 375-380 ◽  
Author(s):  
Koji Yamada ◽  
Hiroshi Mohara ◽  
Tomotaka Kubo ◽  
Takashi Imanaka ◽  
Kazue Iwaki ◽  
...  
Keyword(s):  
Chemical Shifts ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Powdered Sample ◽  
Cationic Sublattice ◽  
81Br Nqr ◽  
Quadrupole Coupling ◽  
Bonding Properties ◽  
Dynamic Structures ◽  
Successive Phase

Structure and bonding properties of InBrx(In5Br7, In2Br3, In4Br7 and InBr2)were studied by 81Br and 115In NQR, and 115In NMR. The ethane-like [Br3InII-InIIBr3]2 anion was confirmed in In5Br7 or In2Br3 by 81Br NQR and the anion was characterized by the high quadrupole coupling constant at the 115In site (e2 Qq/h ≈ 350 MHz). On the other hand, In4Br7 showed successive phase transitions and was characterized as [InI]5[InIIIBr4]2[InIIIBr6] by means of 81Br NQR and 115In NMR below 370 K. A disordered structure at the cationic sublattice was supposed at Phase I above 370 K. NMR signals assigned to the InI could not be detected for the powdered sample, however, all quadrupole coupling constants ( e2Qq/h) and chemical shifts (δiso) could be determined using a single crystal. The InI sites show relatively large e2Qq/h and also show larger distribution of the chemical shift suggesting a diversity of the InI coordination similar to the isoelectronic main group elements such as SnII or SbIII .

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.

Gas-phase electron paramagnetic resonance spectrum and dipole moment of NF( 1 ∆)

1973 ◽  
Vol 332 (1590) ◽  
pp. 355-363 ◽  
Keyword(s):  
Dipole Moment ◽  
Gas Phase ◽  
Resonance Spectrum ◽  
Rotational Level ◽  
Quadrupole Coupling Constant ◽  
Rotational Constant ◽  
Coupling Constants ◽  
Paramagnetic Resonance ◽  
Quadrupole Coupling ◽  
Electron Paramagnetic

The gas-phase paramagnetic resonance spectrum of NF in the J = 2 rotational level of the 1 ∆ state has been studied, and the dipole moment in this state is found to be 0.37 ± 0.60D. The rotational constant previously determined from the electronic spectrum is shown to be consistent with the electron resonance results, and the 14 N quadrupole coupling constant e 2 qQ is 4.1 ± 0.2 MHz. The hyperfine coupling constants of the 14 N and 19 F nuclei are + 109.92 ± 0.14 and +758.06 ± 0.23 MHz respectively.

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

Studies of Successive Phase Transitions and Molecular Motions in [Mg(H2O)6][SiF6] by 1,2H and 19F NMR

1998 ◽  
Vol 53 (6-7) ◽  
pp. 453-458 ◽  
Author(s):  
Junko Kimura ◽  
Takeshi Fukase ◽  
Motohiro Mizuno ◽  
Masahiko Suhara
Keyword(s):  
Phase Transitions ◽  
Nmr Spectra ◽  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Molecular Motions ◽  
Exponential Factor ◽  
H Nmr ◽  
Quadrupole Coupling ◽  
Constant E ◽  
Successive Phase

Abstract The successive phase transitions of [Mg(H2O)6][SiF6] were studied by measuring 2H NMR spectra. The quadrupole coupling constant e2Qq/h and asymmetry parameter η changed drastically at each transition temperature. 1,2H and 19F NMR Tl were measured for this compound to study the relation between the molecular motions and the successive phase transitions. The activation energy Ea and the pre-exponential factor τ0 for the reorientation of [SiF6]2- were estimated as 28 kJmol-1 and 6.0 x 10-14 s, and those of the 180° flip of H2O as 33 kJmol-1 and 4.0x 10-14 s. These two motions occur rapidly even in phase V. For the reorientation of [Mg(H2O)6]2+ , Ea = 62 kJmol-1 and τ0 = 1.1 x 10-16 s were obtained from the simulation of 2H NMR spectra. The jump rate of this motion is of the order of 104 -106 s-1 in phase II. These results suggest that the successive phase transitions are closely related to the motion of [Mg(H2O)6]2+ .

14N Chemical Shifts and Quadrupole Coupling Constants of Inorganic Nitrates

2002 ◽  
Vol 154 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Simon P. Marburger ◽  
B.M. Fung ◽  
A.K. Khitrin
Keyword(s):  
Chemical Shifts ◽  
Coupling Constants ◽  
Quadrupole Coupling

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.

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