The microwave spectrum of the trans conformer of ethyl acetate

D. Jelisavac (1) , D.C. C Cortés Gómez (1) , Ha Vinh Lam Nguyen (1) , L.W. W Sutikdja (1) , Wolfgang Stahl (1) , I. Kleiner (2)

1 RWTH - Rheinisch-Westfälische Technische Hochschule Aachen University
2 LISA (UMR_7583) - Laboratoire Interuniversitaire des Systèmes Atmosphériques

The Fourier transform microwave spectrum of ethyl acetate has been measured under molecular beam conditions. The trans conformer, where all heavy atoms are located within a mirror plane, was identified after analyzing the spectrum by comparison with theoretical calculations. The barrier to internal rotation of the acetate methyl group was found to be only 99.57(11) cm-1 whereas for methyl torsion in the ethyl group a barrier of 1112.3(37) cm-1 was determined. A comparison between two theoretical approaches treating the internal rotation, the so-called RAM (Rho-Axis-Method) and CAM (Combined Axis Method), is also performed.

Mots clés: Microwave spectroscopy; Ethyl acetate; Internal rotation

Domaines: Chimie théorique et/ou physique

D. Jelisavac, D.C. C Cortés Gómez, Ha Vinh Lam Nguyen, L.W. W Sutikdja, Wolfgang Stahl, et al.. The microwave spectrum of the trans conformer of ethyl acetate. Journal of Molecular Spectroscopy, 2009, 257 (2), pp.111-115. ⟨10.1016/j.jms.2009.07.002⟩. ⟨hal-03183174⟩