Title: | Sensing the Molecular Structures of Hexan-2-one by Internal Rotation and Microwave Spectroscopy |
Author(s): | Andresen M; Kleiner I; Schwell M; Stahl W; Nguyen HVL; |
Address: | "Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52074, Aachen, Germany. Laboratoire Interuniversitaire des Systemes Atmospheriques (LISA), CNRS UMR 7583, Universite Paris-Est Creteil, Universite de Paris, Institute Pierre Simon Laplace, 61 avenue du General de Gaulle, F-94010, Creteil, France" |
ISSN/ISBN: | 1439-7641 (Electronic) 1439-4235 (Linking) |
Abstract: | "Using two molecular jet Fourier transform spectrometers, the microwave spectrum of hexan-2-one, also called methyl n-butyl ketone, was recorded in the frequency range from 2 to 40 GHz. Three conformers were assigned and fine splittings caused by the internal rotations of the two terminal methyl groups were analyzed. For the acetyl methyl group CH(3) COC(3) H(6) CH(3) , the torsional barrier is 186.9198(50) cm(-1) , 233.5913(97) cm(-1) , and 182.2481(25) cm(-1) for the three observed conformers, respectively. The value of this parameter could be linked to the structure of the individual conformer, which enabled us to create a rule for predicting the barrier height of the acetyl methyl torsion in ketones. The very small splittings arising from the internal rotation of the butyl methyl group CH(3) COC(3) H(6) CH(3) could be resolved as well, yielding the respective torsional barriers of 979.99(88) cm(-1) , 1016.30(77) cm(-1) , and 961.9(32) cm(-1)" |
Keywords: | ab initio calculations ketones large amplitude motion pheromones rotational spectroscopy; |
Notes: | "PubMed-not-MEDLINEAndresen, Maike Kleiner, Isabelle Schwell, Martin Stahl, Wolfgang Nguyen, Ha Vinh Lam eng ANR-18-CE29-0011/Agence Nationale de la Recherche ANR/International rwth0249/RWTH Aachen University/International Research Support, Non-U.S. Gov't Germany 2019/06/30 Chemphyschem. 2019 Aug 16; 20(16):2063-2073. doi: 10.1002/cphc.201900400. Epub 2019 Jul 18" |