Table 2. Spectroscopic constants for the vibrationally excited states of the EMS conformers.
| Constants/Units | ν 30 trans | 2ν 30 trans | ν 30 gauche |
|---|---|---|---|
| A/MHz | 15813.388(23)a | 15607.23(12) | 9697.268(16) |
| B/MHz | 3183.8596(17) | 3181.0961(52) | 3916.3332(26) |
| C/MHz | 2804.4605(16) | 2810.2753(16) | 3198.8601(19) |
| ΔJ/kHz | 0.7492(23) | 0.7663(26) | 3.2797(43) |
| ΔJK/kHz | -2.3967(91) | -2.3142(31)b | -7.567(38) |
| ΔK/kHz | 53.2(10) | 67.78(13)b | 33.63(40) |
| δJ/kHz | 0.121762(58) | 0.125401(29)b | 1.11790(35) |
| δK/kHz | 0.600(11) | 0.4194(32)b | 7.6065(66) |
| V 3/cm–1 | 689.5(10) | - | - |
| δc/rad | 0.6183(40) | - | - |
| F0/GHz | 158.376d | - | - |
| σrms/kHz | 44.3 | 42.1 | 49.3 |
| Nlines | 61 | 17 | 43 |
| Jmin/Jmax | 13/45 | 13/20 | 12/38 |
| Ka,min/ka,max | 0/4 | 0/1 | 0/7 |
Notes.
a
Numbers in parentheses represent the derived uncertainty (1σ) of the parameter in units of the last digit
b
Kept fixed to the values derived for the ground state of the trans conformer.
c
Angle between the principal axis of the molecule and the internal rotation axis.
d
Fixed to the experimental value previously determined by Hayashi et al. (1981).