THE MICROWAVE SPECTRUM OF PYRUVIC ACID $(CH_{3}COCOOH)$ IN VIBRATIONALLY EXCITED STATES

Abstract

An analysis of the pyruvic acid spectrum has led to the determination of the rotational constants for three excited states of the lowest vibrational mode, the C-C torsion, and for one excited state of the methyl torsion. Relative intensity measurements show that the two vibrations have similar frequencies $(101 ~cm^{-1}$ and $134 ~cm^{-1}$). A least-squares fit of internal rotation splittings in both the ground and first excited states of the methyl torsion has enabled the $V_{3}$ and $V_{6}$ terms in the potential function to be determined.