ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The complete harmonic force field of acetone has been computed at the Hartree–Fock level with the 4–21 basis set of Gaussian orbitals. Seven scale factors optimized for related molecules were used to scale the computed force field. The mean deviation from the experimental vibrational frequencies is only 9.7 cm−1, except for the two methyl torsions. In order to obtain the best possible force field, a new set of seven scale factors was derived by fitting the computed spectrum of acetone to the observed spectrum. The only major change was for the C–C–C bending scaling factor. The final mean deviation was only 5.2 cm−1. The ground state rotational spectra of pyrazole and γ-pyrone have been reinvestigated in the millimeter-wave range. Thanks to millimeter-wave spectroscopy, accurate rotational and centrifugal distortion constants have been determined for acetone, pyrazole, and γ-pyrone. The experimental quartic centrifugal distortion constants are compared with the values calculated from ab initio force fields. A good agreement is found, even for the two-top molecule acetone for which the differences between the experimental and calculated T constants are smaller than 10%.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.460246
