Dipole moments and 14N quadrupole coupling constants in some heterocyclic compounds: all valency electron calculations

1967 ◽  
pp. 1226 ◽  
Author(s):  
D. W. Davies ◽  
W. C. Mackrodt
Keyword(s):  
Heterocyclic Compounds ◽  
Dipole Moments ◽  
Coupling Constants ◽  
Valency Electron ◽  
Quadrupole Coupling

Microwave Spectrum, Quadrupole Coupling Constants, and Dipole Moments of 1-Chloro-2-fluorobenzene

1996 ◽  
Vol 176 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Masao Onda ◽  
Tsuaki Odaka ◽  
Hideya Miyazaki ◽  
Masayoshi Mori ◽  
Ichiro Yamaguchi ◽  
...  
Keyword(s):  
Dipole Moments ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Quadrupole Coupling

Aspects of hybridization

1950 ◽  
Vol 202 (1071) ◽  
pp. 548-564 ◽  
Keyword(s):  
Dipole Moments ◽  
Atomic Orbital ◽  
Second Order ◽  
Coupling Constants ◽  
Covalent Bonds ◽  
Orbital Hybridization ◽  
Quadrupole Coupling ◽  
Orbital Approximation ◽  
Nuclear Quadrupole ◽  
Oxygen Atoms

It has been shown that the pairing theory of orbital hybridization accounts satisfactorily for the variations which are observed in the properties of C-H bonds. Since heteropolar effects are in the opposite directions to the effects described, it is concluded that hybridization influences the properties of predominantly covalent bonds to a greater extent than do differences in electronegativity. The extent of second-order hybridization in the molecules CH, NH and OH has been dealt with in the light of this analysis. The consequences of the electronegativity concept have been examined on the basis of a generalized atomic orbital approximation. In particular, variations of the electronegativity of the carbon, nitrogen and oxygen atoms in different states of hybridization have been analyzed. The idea of 'lone' electrons has been formalized and the results of this definition have been discussed. Finally, the effects of orbital hybridization on the dipole moments and nuclear quadrupole coupling constants of molecules have been considered.

The Charge Distribution in Amides and Thioamides by Nuclear Quadrupole Coupling, Dipole Moments and Electronic Structure Calculations

1996 ◽  
Vol 51 (5-6) ◽  
pp. 460-478
Author(s):  
Michael H. Palmer ◽  
Paul Sherwood
Keyword(s):  
Dipole Moments ◽  
Lone Pair ◽  
Coupling Constants ◽  
Hartree Fock ◽  
Quadrupole Coupling ◽  
Quadrupole Resonance ◽  
Electron Contribution ◽  
Nuclear Quadrupole ◽  
Moller Plesset ◽  
Structure Calculations

AbstractThe nuclear quadrupole coupling constants from microwave spectroscopy (MW) and quadrupole resonance (NQR) for amides and thioamides are discussed in relation to Hartree-Fock calculations with and without Moller-Plesset correlation effects. The view that the larger dipole moments from thioamides than the corresponding amides is a function of enhanced resonance in the former is discussed and (in effect) confirmed by the present procedures. The principal mechamism seems to be the push/pull π/σ effects of the N atom with respect to the CO and CS groups, with S being a better σ-donor than O; however, the effect is still present with formamidine where no electronegativity effects are important, so the overall effect is the 2,1,1 π-electron contribution to the allylic system from N, C, O(S). The use of localised MO’s and NO’s is described, and the centroid positions are discussed in relation to the polarity of the bonds. The LMO’s largely truncate the contributions to each NQCC to the three attached bonds (or 2 bonds + a lone pair orbital at O or S), as is used in the Townes-Dailey procedures. More distant LMO’s generally contribute < 0.05 a. u. to the EFG, simplifying the analysis. The effects of O( or S)-protonation of urea and thiourea is discussed.

Microwave Absorption Spectra of AlF, GaF, InF, and TIF

1970 ◽  
Vol 25 (7) ◽  
pp. 1029-1035 ◽  
Author(s):  
J. Hoeft ◽  
F. J. Lovas ◽  
E. Tiemann ◽  
T. Törring
Keyword(s):  
Vibrational State ◽  
Stark Effect ◽  
Dipole Moments ◽  
Electric Quadrupole ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Vibrational States ◽  
Electric Dipole Moments ◽  
Quadrupole Coupling

Observation of various rotational transitions of four Group Ilia monofluoride allowed the Dunham coefficients Y01, Y11, Y21 and Y12 to be determined. From the hyperfine structure of the AlF, GaF and InF spectra, the nuclear electric quadrupole coupling constants, e qv Q, and spin-rotation coupling constant, CI, were obtained for several vibrational states, v: e qv Q(27 Al19F) = -37,75(8) + 0,44(8) (v + 1/2) MHz,e qv Q(69 Ga19F) = -107,07(8) + 1,09(7) (v + 1/2) MHz,e qv Q(71 Ga19F) = -67,46(8) + 0,68(7) (v + 1/2) MHz,e qv Q(115 In19F) = -727,06(20) + 6,64(20) (v + 1/2) MHz.Stark effect measurements on GaF and InF in the ground vibrational state resulted in the following electric dipole moments:69Ga 19F: |μ̄| = 2,45 (5) D,115In 19F: |μ̄| = 3,40 (7) D

scholarly journals Precise dipole moments and quadrupole coupling constants of the cis and trans conformers of 3-aminophenol: determination of the absolute conformation

2008 ◽  
Vol 10 (5) ◽  
pp. 666-673 ◽  
Author(s):  
Frank Filsinger ◽  
Kirstin Wohlfart ◽  
Melanie Schnell ◽  
Jens-Uwe Grabow ◽  
Jochen Küpper
Keyword(s):  
Dipole Moments ◽  
Coupling Constants ◽  
Quadrupole Coupling ◽  
The Absolute ◽  
Cis And Trans

COMPUTATIONAL STUDY OF A CNT-URACIL-CNT COMPOUND

2011 ◽  
Vol 25 (15) ◽  
pp. 1335-1341 ◽  
Author(s):  
MARYAM MIRZAEI ◽  
MOHAMMAD YOUSEFI ◽  
MAHMOUD MIRZAEI
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Computational Study ◽  
Dipole Moments ◽  
Coupling Constants ◽  
Modification Process ◽  
Quadrupole Coupling ◽  
Electronic Environments ◽  
Oxygen Atoms

Density functional calculations were performed to investigate the properties of a combination of two representative carbon nanotubes by assistance of the atomic sites of uracil, which is the characteristic nucleobase of RNA. The obtained parameters indicated that the resulting compound exhibit new properties with respect to the original nanotubes and uracil. The effects of the modification process were significant for the dipole moments and conductivity properties of the components as were seen by the significant changes in the new compound. The values of quadrupole coupling constants for the nitrogen and oxygen atoms of the uracil counterpart of the investigated models also indicated the effects of changes of the electronic environments of the components due to the modification process.

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