The rotational spectrum of 2'-aminoacetophenone has been recorded and assigned using a Stark-modulated Free-Jet Absorption Millimeter-Wave (FJ-AMMW) spectrometer in the 59.6-74.4 GHz frequency range. Some transition lines show a hyperfine structure due to the internal rotation of the methyl group. A global fitting including previous measurements performed in the microwave region allowed the determination of the DJ and DK quartic centrifugal distortion constants and methyl internal rotation barrier V 3 = 644(3) cm-1 value. The A-E tunnelling splitting is estimated to be d 0 = 23 MHz. Calculations at the MP2/aug-cc-pVTZ level underestimate the height of the V 3 barrier by about 23 cm-1. This difference increases to 150 cm-1 with B3LYP-D3(BJ)/Def2-TZVP.
Boi, S., Melandri, S., Evangelisti, L., Maris, A. (2025). Free-jet absorption millimeter-wave spectrum of 2’-aminoacetophenone. JOURNAL OF MOLECULAR SPECTROSCOPY, 407(111966), 1-4 [10.1016/j.jms.2024.111966].
Free-jet absorption millimeter-wave spectrum of 2’-aminoacetophenone
Melandri S.Secondo
;Evangelisti L.Penultimo
;Maris A.
Ultimo
2025
Abstract
The rotational spectrum of 2'-aminoacetophenone has been recorded and assigned using a Stark-modulated Free-Jet Absorption Millimeter-Wave (FJ-AMMW) spectrometer in the 59.6-74.4 GHz frequency range. Some transition lines show a hyperfine structure due to the internal rotation of the methyl group. A global fitting including previous measurements performed in the microwave region allowed the determination of the DJ and DK quartic centrifugal distortion constants and methyl internal rotation barrier V 3 = 644(3) cm-1 value. The A-E tunnelling splitting is estimated to be d 0 = 23 MHz. Calculations at the MP2/aug-cc-pVTZ level underestimate the height of the V 3 barrier by about 23 cm-1. This difference increases to 150 cm-1 with B3LYP-D3(BJ)/Def2-TZVP.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
