Barrier to internal rotation in ethane from the microwave spectrum of CH3CHD2

• DOI: 10.1063/1.438464
• Publication Date: 2003-02-27T21:39:21Z
• Authors: Eizi Hirota; Shuji Saito; Yasuki Endo
• Keywords: Internal Rotation; Distortion (music); Modulation (music); Rotational spectrum

Rotational spectra of CH3CHD2 were observed by using a source-modulation microwave spectrometer. Of 26 transitions, 16 showed splittings due to internal rotation. An analysis the spectra, which utilized an axis method modified include centrifugal distortion effects, gave following results: A=60 809.592 (59) MHz, B=17 770.87 (16) C=17 084.84 F=257.70 (35) GHz, and V3=2.8783 (28) kcal/mole, with 2.5 times standard errors in parentheses. In V6=0 was assumed, D, constant associated cross product inertia, fixed calculated value. When uncertainty D is taken into account, error V3 increases 0.0029 kcal/mole. Effects molecular vibrations on barrier are discussed briefly.