Random-Coil Configurations of Polymeric Chains with Sulfur and Oxygen Atoms in Their Structure: Dipole Moments of Poly(1,3-dioxa-6-thiocane)

1979 ◽  
Vol 12 (6) ◽  
pp. 1117-1120 ◽  
Author(s):  
E. Riande ◽  
J. Guzmán
Keyword(s):  
Dipole Moments ◽  
Random Coil ◽  
Polymeric Chains ◽  
Oxygen Atoms

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.

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.

Variability of shapes and properties of atoms in molecules: a case study of the carbonyl oxygen

1996 ◽  
Vol 74 (6) ◽  
pp. 1263-1270 ◽  
Author(s):  
Boris B. Stefanov ◽  
Jerzy Cioslowski
Keyword(s):  
Electronic Properties ◽  
Dipole Moments ◽  
Visual Assessment ◽  
Carbonyl Oxygen ◽  
Atoms In Molecules ◽  
Large Molecules ◽  
Neighbor Effects ◽  
Theoretical Considerations ◽  
Oxygen Atoms

A comparative study of carbonyl oxygen atoms in diverse molecular environments is presented. The variability of shapes of oxygen atoms is quantified with a newly developed similarity measure that confirms the qualitative conclusions of visual assessment. Electronic properties of these atoms, such as charges, energies, and dipole moments, are computed and their possible correlations with the atomic shapes are studied. Factors that affect atomic shapes are investigated and found to be distinct from those influencing electronic properties of atoms in molecules. The kinetic energies of the atoms under study correlate poorly with the atomic charges. The second-neighbor effects on the atomic energies and charges are approximately additive. Both the theoretical considerations and the numerical results definitively rule out the possibility of the shapes of atomic basins unambiguously determining the properties of atoms in molecules. The consequences of this observation for the recently contemplated approaches to the prediction of electronic properties of large molecules are discussed. Key words: atoms in molecules, properties of —; similarity of —; transferability of —.

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