Author

10.37652/juaps.2011.15271

Abstract

ABSTRACT.:Density Functional Theory (DFT) of the type (B3LYP) and a Gaussian basis (6-311G)
was applied for calculating the vibration frequencies and IR absorption intensities for normal
coordinates of the ([6] Cyclacene (Chiral), with (D3d) symmetry) molecule. Comparison of the results
showed that for the C-H stretching vibrations the sym. modes show higher frequency values than the
asym. And the inverse for C-C stretching vibrations.
As for the CH and CC deformation the asym. vibrations where of lower frequency values than the
sym.;
sym.CH str. > asym. CH str.
sym CC str. < asym. CC str.
 C=C str. (circum.) >  C--C str. (axial.) >  C-C str. (circum.)
And,sym. δCH > asym. δCH
sym. CH < asym. CH
δCH (rocking) > δCH (scissoring)
CH (twisting) > CH (wagging)
Where axial are the vertical C-C bonds (annular bonds) in the rings and circumferential are the outer
ring bonds.
The results include the assignment of all puckering, breathing and clock-anticlockwise bending
vibrations. Also calculations and studying the distribution of electronic density on the atoms of the
molecule. They allow a comparative view of the charge density at the carbon atoms too

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