On the deuteron quadrupole coupling constant in hydrogen bonded solids

1974 ◽  
Vol 60 (5) ◽  
pp. 1892-1893 ◽  
Author(s):  
Shaul D. Goren
Keyword(s):  
Quadrupole Coupling Constant ◽  
Coupling Constant ◽  
Quadrupole Coupling ◽  
Hydrogen Bonded

Second sphere coordination of phenols, anilines, and benzoic acids to the hexacyanocobaltate(III) anion

1983 ◽  
Vol 61 (7) ◽  
pp. 1524-1531 ◽  
Author(s):  
Donald R. Eaton ◽  
Richard J. Buist ◽  
Carol V. Rogerson
Keyword(s):  
Hydrogen Bond ◽  
Correlation Time ◽  
Chemical Shifts ◽  
Equilibrium Constants ◽  
Quadrupole Coupling Constant ◽  
Benzoic Acids ◽  
Coupling Constant ◽  
Line Broadening ◽  
Quadrupole Coupling ◽  
Hydrogen Bonded

Complexing between the hexacyanocobaltate(III) anion and ten substituted phenols, eight substituted anilines, and eight substituted benzoic acids has been studied in dimethyl sulfoxide solutions by means of 59Co nmr. For the phenols substantial changes in the chemical shifts and in the line widths are observed and are attributed to hydrogen bonding interactions. Effective equilibrium constants and chemical shifts for the hydrogen bonded species have been calculated. The equilibrium constants vary with the phenol substituent, being largest for electron withdrawing substituents and smallest for electron donating substituents. The chemical shifts are virtually independent of substituent. The data show that the lifetimes of the hydrogen bonded complexes are long compared to the rotational correlation time. The complex with para-nitrophenol has also been studied by measuring 1H and 13C spin–lattice relaxation times. These measurements allow the separation of the increase in 59Co line width due to increase in correlation time and that due to increase in quadrupole coupling constant. From the 13C measurements a value of the correlation time for the complex of 2.8 10−1 s is obtained together with a 59Co quadrupole coupling constant of 8.34 MHz. The equilibrium constants for complex formation with the anilines are small and only the products of the equilibrium constant and the chemical shift of the hydrogen bonded complex can be derived from the experimental data. The benzoic acids show evidence of dimerization in solution and this again prevents the calculation of absolute equilibrium constants. The data, however, do indicate that the ability to form hydrogen bond complexes does not vary dramatically with the acid strength of the hydrogen donor. With phenols and benzoic acids there is considerable line broadening on complex formation but with anilines only a small line broadening is observed. This is consistent with very short hydrogen bond lifetimes for the aniline complexes.

Conformational Analysis of Chloromethylenimine and its Hydrogen-Bonded Dimers with Water from the Study of Nuclear Quadrupole Interactions

1996 ◽  
Vol 51 (5-6) ◽  
pp. 534-536 ◽  
Author(s):  
N. Sathyan ◽  
V. Santhanam ◽  
J. Sobhanadri
Keyword(s):  
Proton Affinity ◽  
Quadrupole Coupling Constant ◽  
Basis Set ◽  
Coupling Constant ◽  
Quadrupole Interactions ◽  
Nuclear Quadrupole Interactions ◽  
Nuclear Quadrupole Coupling Constant ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Hydrogen Bonded

Abstract A molecular conformation study on N-Chloromethylenimine and its 1:1 dimeric form with water has been carried out using the ab-initio method at 6-31 G and 6-31 G* basis set. We consider the two most stable conformers of the N-chloromethylenimine -water binary mixture involving double hydrogen bonds. In all cases the proton affinity has been calculated. Each system considered in this work has the nuclear quadrupole interactions of the nitrogen and chlorine resonant nuclei which have been calculated and compared. It is found that the nuclear quadrupole coupling constant for the nitrogen nucleus increases in the hydrogen bonded complexes and decreases for the chlorine nucleus compared to the monomeric values. The influence of proton affinity is reflected in the nuclear quadrupole coupling constant.

Improved Rotational Constants and Dipole Moment and a Nuclear Quadrupole Coupling Analysis of 2-Cyanothiophene and Dipole Moment of 2-Cyanofurane

1977 ◽  
Vol 32 (2) ◽  
pp. 152-155 ◽  
Author(s):  
J. Wiese ◽  
L. Engelbrecht ◽  
H. Dreizler
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Dipole Moments ◽  
Quadrupole Coupling Constant ◽  
Rotational Constant ◽  
Coupling Constant ◽  
Frequency Range ◽  
Effect Analysis ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Results of a microwave investigation of the molecules 2-Cyanothiophene and 2-Cyanofurane are reported. The microwave spectrum of 2-Cyanothiophene was examined in the frequency range of 13 -40 GHz mainly to get a more accurate rotational constant A from the assignment of μb-btransitions. From the resolved hyperfine structure due to nuclear quadrupole coupling of the 14N-nucleus the quadrupole coupling constant X+=Xbb + Xcc was determined for 2-Cyanothiophene. No information for X- was available from the measured transitions.From Stark effect studies the dipole moments were determined for both molecules. The nuclear quadrupole coupling as a perturbation of the second order Stark effect was included in the Stark effect analysis

scholarly journals Two-Dimensional Nutation NQR Broad-Line Spectra in Oriented Samples

2006 ◽  
Vol 61 (9) ◽  
pp. 499-504 ◽  
Author(s):  
Nicolay Sinyavsky ◽  
Irina Korneva ◽  
Michał Ostafin ◽  
Bolesław Nogaj ◽  
Mariusz Maćkowiak
Keyword(s):  
Asymmetry Parameter ◽  
Disordered Systems ◽  
Quadrupole Coupling Constant ◽  
Two Dimensional ◽  
Coupling Constant ◽  
Nuclear Spins ◽  
Radio Frequency Field ◽  
Quadrupole Coupling ◽  
Oriented Samples ◽  
Constant E

The NQR nutation method to determine the electric field gradient asymmetry parameter η in systems, where the resonance line is so broad that the radio frequency field can excite only a portion of the nuclear spins, is presented. In this situation, the recently developed spectroscopic methods are not applicable. Two-dimensional nutation NQR spectra of oriented powders are calculated and used to determine η at particular frequencies along a broad NQR line. The proposed method is useful for single crystals, oriented powders, glasses, and disordered systems even for small values of the asymmetry parameter. Therefore it can be used to evaluate fluctuations in η and the quadrupole coupling constant e2qQ due to inhomogeneities. We demonstrate the application of this method to oriented chalcogenide semiconducting glasses.

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