The rotational spectrum of (Formula presented.) -hydroxyacetophenone has been recorded and assigned for the first time using a Stark-modulated free-jet absorption millimeter-wave (FJ-AMMW) spectrometer in the 59.6–74.5 GHz frequency range. The most stable conformer has been detected and assigned: A = 2277.076(11), B = 1212.113(5) and C = 795.278(5) MHz. It is characterized by a (Formula presented.) symmetry where a strong hydrogen bond between the acetyl oxygen atom and the hydroxyl atom takes place. The transition lines show a fine structure due to the internal rotation of the methyl group, which allowed the determination of a (Formula presented.) = 565.1(5) (Formula presented.) barrier. The corresponding tunneling splittings have been estimated to be 51 MHz. Calculations at the B3LYP-D3(BJ)/Def2-TZVP level underestimate the height of the barrier by about 156 (Formula presented.). This value decreases to 25 (Formula presented.) with MP2/aug-cc-pVTZ.
Boi, S., Melandri, S., Evangelisti, L., Maris, A. (2024). Molecular Structure and Internal Dynamics of 2′-Hydroxyacetophenone by Free-Jet Absorption Millimeter-Wave Spectroscopy. MOLECULES, 29(24), 1-9 [10.3390/molecules29245842].
Molecular Structure and Internal Dynamics of 2′-Hydroxyacetophenone by Free-Jet Absorption Millimeter-Wave Spectroscopy
Melandri S.Secondo
;Evangelisti L.Penultimo
;Maris A.
Ultimo
2024
Abstract
The rotational spectrum of (Formula presented.) -hydroxyacetophenone has been recorded and assigned for the first time using a Stark-modulated free-jet absorption millimeter-wave (FJ-AMMW) spectrometer in the 59.6–74.5 GHz frequency range. The most stable conformer has been detected and assigned: A = 2277.076(11), B = 1212.113(5) and C = 795.278(5) MHz. It is characterized by a (Formula presented.) symmetry where a strong hydrogen bond between the acetyl oxygen atom and the hydroxyl atom takes place. The transition lines show a fine structure due to the internal rotation of the methyl group, which allowed the determination of a (Formula presented.) = 565.1(5) (Formula presented.) barrier. The corresponding tunneling splittings have been estimated to be 51 MHz. Calculations at the B3LYP-D3(BJ)/Def2-TZVP level underestimate the height of the barrier by about 156 (Formula presented.). This value decreases to 25 (Formula presented.) with MP2/aug-cc-pVTZ.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
