Rotational Spectrum of Eugenol As Analyzed with Double Resonance and Grid-Based Autofit

The molecule eugenol was extracted from cloves via steam-distillation, and its rotational spectrum from 3–18 GHz was acquired with a chirped-pulsed Fourier transform microwave spectrometer. This spectrum was analyzed via two separate methods in parallel, one employing several microwave–microwave double resonance measurements and the other using a newly written version of the Autofit program. Both methods yielded rotational constants in excellent agreement with predictions from ab initio calculations. The relative merits of the different analysis methods are discussed.