ChemInform Abstract: The Microwave Spectrum of 4-Methylenecyclohexene

The microwave spectrum of 4-methylenecyclohexene has been observed in the frequency range 12–40 GHz and the spectra of the ground and nine excited vibrational states of a single conformer have been assigned. Relative intensity measurements give 104(27) cm −1 and 161(33) cm −1 for the two lowest vibrational frequencies. The microwave spectrum is consistent with a high barrier to ring inversion.