CNDO/2 study of some polyvalent iodine compounds. I. Negative ions

1974 ◽  
Vol 27 (7) ◽  
pp. 1381 ◽  
Author(s):  
RW Hollingworth ◽  
S Hacobian
Keyword(s):  
Molecular Orbital ◽  
Negative Ions ◽  
Force Constants ◽  
Coupling Constants ◽  
Molecular Orbital Calculations ◽  
Harmonic Force ◽  
Iodine Compounds ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Equilibrium Geometries

A study has been made of the bonding of some negative polyvalent iodine ions by means of CNDO/2 molecular orbital calculations. The theoretical equilibrium geometries, harmonic force constants, nuclear quadrupole coupling constants and charge distributions have been calculated. The results tend to confirm the Pimentel theory of bonding, whereby iodine achieves its polyvalence through the delocalization of electrons in the molecular orbital composed of the bonding p-orbitals of the atoms in the ions.

Microwave Spectra of Furazan II. Nuclear Quadrupole Coupling in d1-Furazan

1988 ◽  
Vol 43 (6) ◽  
pp. 607-613 ◽  
Author(s):  
Otto L. Stiefvater
Keyword(s):  
Structural Information ◽  
Radial Electric Field ◽  
Coupling Constants ◽  
Molecular Orbital Calculations ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Data Yield ◽  
Preceding Study

Abstract The nuclear quadrupole coupling constants for the two nitrogen atoms in monodeuterated furazan (C2HDN2O) were determined from the hyperfine structure of eight rotational transitions with low J-values. The coupling constants along the inertial axes are: χaa (2) = + 3.546(10) MHz, χaa (5) = -5.044(10) MHz, χbb (2) = -4.690(10) MHz, χbb (5) = + 3.900(10) MHz, χcc (2) = + 1.144(10) MHz, χcc (5) = + 1.144(10) MHz. In conjunction with structural information from the preceding study, these data yield the principal coupling constants, with 3er-uncertainties, as: χR(2/5) = - 5.53 (4) MHz, χT(2/5) = + 4.39(4)MHz, χR(2/5) = + 1.14(4) MHz. The radial electric field gradients deviate from the direction of the external bisector of the ring angle ONC by 24.6° towards the oxygen atom. These results are in qualitative agreement with previous work by NQR spectroscopy and with the results of ab initio molecular orbital calculations.

scholarly journals Nuclear Quadrupole Coupling in 5-Membered Ring Oxygen and Sulphur Heterocyclic Compounds; Studies by Nuclear Quadrupole Resonance and Ab Initio Molecular Orbital Calculations

1979 ◽  
Vol 34 (2) ◽  
pp. 220-232 ◽  
Author(s):  
Mavis Redshaw ◽  
Michael H. Palmer ◽  
Robert H. Findlay
Keyword(s):  
Ab Initio ◽  
Nuclear Quadrupole Resonance ◽  
Principal Axis ◽  
Coupling Constants ◽  
Molecular Orbital Calculations ◽  
Quadrupole Coupling ◽  
Quadrupole Resonance ◽  
Nuclear Quadrupole ◽  
High Level ◽  
Level Of Agreement

Abstract The 14N nuclear quadrupole resonance spectra for the compounds 2a, b, 3b, 4b, 5a, b, 6b have been obtained at 77 K and the asymmetry parameter and coupling constants extracted. A comparison of these with microwave spectral results, shows that small but systematic differences occur between the solid and gaseous states. There is a high level of agreement for the observed coupling constants from NQR or MW spectra and the ab initio calculations in both magnitude and direction. This enables us to extract further principal axis data from the observed microwave spectra, and to predict with some confidence the axes and coupling magnitudes for other members of the series where incomplete determinations are available. Variations in coupling constants with structure are discussed

19F Nuclear Quadrupole Coupling in some Halomethanes

1986 ◽  
Vol 41 (1-2) ◽  
pp. 171-174 ◽  
Author(s):  
M. Frank ◽  
F. Gubitz ◽  
W. Ittner ◽  
W. Kreische ◽  
A. Labahn ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Simple Model ◽  
Temperature Dependence ◽  
Coupling Constants ◽  
Temperature Dependent ◽  
Distribution Method ◽  
Quadrupole Coupling ◽  
Time Differential ◽  
Nuclear Quadrupole

The 19F quadrupole coupling constants in CF4, CHF3, CClF3 and CHClF2 are reported. The measurements were carried out temperature dependent using the time differential perturbed angular distribution method (TDPAD). The temperature dependence can be satisfactorily described in the framework of the Bayer-Kushida theory. A simple model is used to explain the appearance of H-F and Cl-F coupling constants in CHF3/CHClF2 and CClF3, respectively.

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