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Conformational landscapes of symmetrically fluorine-substituted benzoic acids II: Calculations and measurements for the rotational spectrum and structure of 3,4,5-trifluorobenzoic acid.
- Source :
-
Journal of Molecular Spectroscopy . Sep2023, Vol. 397, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
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Abstract
- [Display omitted] • First microwave spectroscopic study of 3,4,5-trifluorobenzoic acid. • Precise determination of rotational constants for nine isotopologues. • Molecular structure determined for 3,4,5-trifluorobenzoic acid. • Good agreement between experimental and calculated spectroscopic parameters. Calculations on the structure of 3,4,5-trifluorobenzoic acid were made using the Gaussian 16 program. The potential energy surfaces were scanned along C C C O and O C O H dihedral angles at the B3LYP/6-311G level to analyze its conformational landscape. Two conformations were identified and reoptimized at the B3LYP/aug-cc-pVTZ level. The result indicates that 3,4,5-trifluorobenzoic acid prefers a planar structure in its global minimum conformation. The pure rotational spectra of 3,4,5-trifluorobenzoic acid were measured in the frequency range of 6 – 12.5 GHz using a chirped pulse Fourier transform microwave (CP-FTMW) spectrometer. The spectra of the parent, seven 13C, and one deuterium singly substituted isotopologues were analyzed and fitted to measurement accuracy for a semi-rigid asymmetric top molecule. The rotational constants and centrifugal distortion constants were accurately determined. The rotational constants for the parent isotopologue are A = 1535.31408(32) MHz, B = 650.31751(16) MHz, and C = 456.98499(12) MHz. The effective structure of its ground vibrational state was determined from the spectra of the mono-substituted isotopologues. The agreement between the calculated and experimental spectroscopic constants is excellent. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00222852
- Volume :
- 397
- Database :
- Academic Search Index
- Journal :
- Journal of Molecular Spectroscopy
- Publication Type :
- Academic Journal
- Accession number :
- 173372387
- Full Text :
- https://doi.org/10.1016/j.jms.2023.111837