Table 2. Experimental spectroscopic parameters determined for the observed conformers of serinol.
| I | II | III | IV | V | |
| A a (MHz) | 6049.9322(41) e | 5981.6740(48) | 4208.5954(10) | 7679.4716(36) f | 5327.3056(33) |
| B (MHZ) | 2265.0200(11) | 2257.0848(12) | 3130.7067(12) | 1968.9155(10) | 2367.0593(11) |
| C (MHz) | 1981.1930(13) | 1965.8411(14) | 2527.3601(15) | 1689.0099(12) | 1762.9563(12) |
| Δ J (kHz) | 0.482(46) | 0.409(45) | 0.920(90) | 0.293(29) | 0.636(43) |
| Δ JK (kHz) | — | — | — | 2.051(25) | –0.971(22) |
| Δ K (kHz) | 7.69(10) | 6.34(11) | — | — | — |
| χ aa (MHz) | –0.299(11) | –3.9203(77) | –2.3658(73) | –3.2357(72) | –3.8976(90) |
| χ bb (MHz) | 2.338(13) | 2.388(13) | 1.228(10) | 1.640(14) | 2.252(13) |
| χ cc (MHz) | –2.039(13) | 1.533(13) | 1.138(10) | 1.596(14) | 1.646(13) |
| ΔE (MHz) | — | — | — | 0.2943(20) | — |
| σ b (kHz) | 14 | 14 | 13 | 14 | 13 |
| N c | 60 | 66 | 62 | 92 | 62 |
| a/b/c d | y/y/y | y/y/y | y/y/y | y/y/y | y/y/y |
a A, B, and C are the rotational constants; Δ J, Δ JK, and Δ K are the quartic centrifugal distortion constants; χ aa, χ bb, and χ cc are 14N nuclear quadrupole coupling constants; ΔE is the difference in energy between the two tunnelling states of serinol IV.
brms deviation of the fit.
cNumber of hyperfine transitions.
dYes (y) or no (n) observation of a-, b-, and c-type transitions.
eStandard error in parentheses in the units of the last digit.
fThe rotational constants obtained for each tunneling state were the same, within experimental error, when fitted separately.