Methyl Internal Rotation in the Microwave Spectrum of Vinyl Acetate

作者：Ha Vinh Lam Nguyen^*; Jabri Atef; Van Vinh; Stahl Wolfgang

来源：Journal of Physical Chemistry A, 2014, 118(51): 12130-12136.

DOI：10.1021/jp5075829

The rotational spectrum of vinyl acetate, CH3(CO)OCH=CH2, was measured using two molecular beam Fourier transform microwave spectrometers operating in the frequency range from 2 to 40 GHz. Large splittings up to 2 GHz occurred due to the internal rotation of the acetyl methyl group CH3CO with a V-3 potential of 151.492(34) cm(-1), much larger than the barrier of approximately 100 cm(-1) often found in acetates. The torsional transitions were fitted using three different programs XIAM, ERHAM, and BELGI-Cs, whereby the rotational constants, centrifugal distortion constants, and the internal rotation parameters could be determined with very high accuracy. The experimental results were supported by quantum chemical calculations. For a conformational analysis, potential energy surfaces were calculated.

• 出版日期2014-12-25