Combined microwave-optical barrier determination for molecules with a heavy symmetric internal top: CF3NO and CF3CHO
✍ Scribed by David W. Knight; A.Peter Cox
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 441 KB
- Volume
- 132
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
The torsional data for CF,NO have been reinvestigated. A model with a single degree of freedom and three adjustable parameters is sufficient to fit data to u = 8 in the electronic ground state. For CF3NO we obtain F,J = 1.9822(42) cm-', V3 = 238.4(1.6) cm-l and V6 = -5.8(1.6) cm-' or Fo = 1.9894(66) cm -l, F, = -0.194(55) cm-' and V3 = 239.3(1.9) cm-'. A similar treatment for CF&HO gives F 0 = 1.97( ) cm-', V3 = 305(25) cm-l and V, = -8.7(1.2) cm-'. A need for a reexamination of the torsional fundamental is indicated for CF3CHO. These studies support the general conclusion that for a heavy internal top the internal rotation constant, Fo, required to fit a range of torsional splittings is different from that calculated from structural considerations alone. The difference indicates a large change in F with torsional averaging.