Table 2.
Molecular parameters of the two assigned conformers I (C1) and XIII (Cs) of MHO obtained from a fit with the program XIAM.
| Par. a | Unit | I = C1 | XIII = Cs |
|---|---|---|---|
| A | MHz | 3599.03841(24) | 6987.3630(32) |
| B | MHz | 625.35951(20) | 483.652(15) |
| C | MHz | 585.83319(20) | 460.364(16) |
| ΔJ | kHz | 0.17529(66) | 0.0393(91) |
| ΔJK | kHz | −4.7630(45) | |
| ΔK | kHz | 45.278(21) | 6.13(65) |
| δJ | kHz | 0.01954(32) | 0.0027(11) |
| δK | kHz | −0.824(82) | 27.8(76) |
| V3 b | cm−1 | 415.15(13) | 416.890(96) |
| ∠(i,a) | ° | 134.280(79) | 158.82(12) |
| ∠(i,b) | ° | 133.80(40) | 68.82(12) |
| ∠(i,c) | ° | 79.46(95) | 90.0 c |
| N A /N E d | 100/80 | 21/21 | |
| σ e | kHz | 4.0 | 4.4 |
a All parameters refer to the principal axis system. Watson’s A reduction in Ir representation was used. The errors in parentheses are in the unit of the last significant digits. b The V3 parameter is correlated to the moment of inertia F0 of the methyl rotor. Therefore, F0 was fixed to 158 GHz in both fits, a value often found for methyl groups and also used in Refs. [17,18], corresponding to a moment of inertia of Iα = 3.2 uÅ2. c Fixed due to symmetry. d Number of the A (NA) and E species lines (NE). e Standard deviation of the fit.