Details
Original language | English |
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Article number | 131096 |
Journal | Journal of molecular structure |
Volume | 1246 |
Early online date | 15 Jul 2021 |
Publication status | Published - 15 Dec 2021 |
Abstract
The rotational spectrum of 2-fluoro-4-chlorotoluene was studied in the frequency range 4 to 24 GHz by Fourier transform microwave spectroscopy. Fine torsional splittings into doublets were found for all rotational transitions due to methyl internal rotation hindered with a barrier of about 230 cm−1. In combination with the quadrupole coupling hyperfine splittings on the same order of magnitude originating from the chlorine nucleus, rich spectral features were observed. Rotational and quadrupole coupling constants for the 35Cl and 37Cl isotopologues studied in natural abundance were precisely determined. Results from the experiment were supported by quantum chemical calculations at several levels of theory for the rotational constants and by Bailey's semi-experimental method for the quadrupole coupling constants. The χcc quadrupole coupling tensor element and the barrier to methyl internal rotation were compared with those of other halogen-substituted toluene derivatives.
Keywords
- Chlorine nuclear quadrupole coupling, Internal rotation, Large amplitude motion, Microwave spectroscopy
ASJC Scopus subject areas
- Chemistry(all)
- Analytical Chemistry
- Chemistry(all)
- Spectroscopy
- Chemistry(all)
- Organic Chemistry
- Chemistry(all)
- Inorganic Chemistry
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In: Journal of molecular structure, Vol. 1246, 131096, 15.12.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Neighborhood matters
T2 - Steric effects on methyl internal rotation and chlorine nuclear quadrupole coupling in 2-fluoro-4-chlorotoluene
AU - Nair, K. P.Rajappan
AU - Herbers, Sven
AU - Grabow, Jens Uwe
AU - Nguyen, Ha Vinh Lam
N1 - Funding Information: The authors thank the Land Niedersachsen and the Deutsche Forschungsgemeinschaft (DFG) for funding. This work was supported by the Agence Nationale de la Recherche ANR (project ID ANR-18-CE29–0011). We greatly acknowledge Dr. V. Ilyushin for his help in performing the RAM36hf fits and for making his code available to the spectroscopic community. We also thank Dr. W.C. Bailey for checking our NQCC calculations.
PY - 2021/12/15
Y1 - 2021/12/15
N2 - The rotational spectrum of 2-fluoro-4-chlorotoluene was studied in the frequency range 4 to 24 GHz by Fourier transform microwave spectroscopy. Fine torsional splittings into doublets were found for all rotational transitions due to methyl internal rotation hindered with a barrier of about 230 cm−1. In combination with the quadrupole coupling hyperfine splittings on the same order of magnitude originating from the chlorine nucleus, rich spectral features were observed. Rotational and quadrupole coupling constants for the 35Cl and 37Cl isotopologues studied in natural abundance were precisely determined. Results from the experiment were supported by quantum chemical calculations at several levels of theory for the rotational constants and by Bailey's semi-experimental method for the quadrupole coupling constants. The χcc quadrupole coupling tensor element and the barrier to methyl internal rotation were compared with those of other halogen-substituted toluene derivatives.
AB - The rotational spectrum of 2-fluoro-4-chlorotoluene was studied in the frequency range 4 to 24 GHz by Fourier transform microwave spectroscopy. Fine torsional splittings into doublets were found for all rotational transitions due to methyl internal rotation hindered with a barrier of about 230 cm−1. In combination with the quadrupole coupling hyperfine splittings on the same order of magnitude originating from the chlorine nucleus, rich spectral features were observed. Rotational and quadrupole coupling constants for the 35Cl and 37Cl isotopologues studied in natural abundance were precisely determined. Results from the experiment were supported by quantum chemical calculations at several levels of theory for the rotational constants and by Bailey's semi-experimental method for the quadrupole coupling constants. The χcc quadrupole coupling tensor element and the barrier to methyl internal rotation were compared with those of other halogen-substituted toluene derivatives.
KW - Chlorine nuclear quadrupole coupling
KW - Internal rotation
KW - Large amplitude motion
KW - Microwave spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85111534623&partnerID=8YFLogxK
U2 - 10.1016/j.molstruc.2021.131096
DO - 10.1016/j.molstruc.2021.131096
M3 - Article
AN - SCOPUS:85111534623
VL - 1246
JO - Journal of molecular structure
JF - Journal of molecular structure
SN - 0022-2860
M1 - 131096
ER -