Knowledge Bank

Rotationally-resolved jet-cooled and room temperature spectra of the previously unobserved $\nu 3$ CH stretch of vinoxy radical $(CH2CHO)$ have been obtained near $2800cm-1$ by means of tunable infrared laser spectroscopy (difference frequency generation technique). About 480 transitions corresponding to b-type selection rules have been assigned in the jet-cooled spectrum recorded in the region $2809-2860cm-1$. The band origin has been determined to be $2827.9125cm-1$. A number of lines are split into doublets by the electron spin-rotation interaction. The more congested room temperature spectrum has been recorded over the spectral region $2754-2894cm-1$. With the aid of the analysis of the jet-cooled spectrum, more than 440 room temperature lines mostly corresponding to transitions with high K or high N values have been assigned. Both local and extensive global perturbations have been found in the upper state energy levels. Least squares fitting of the apparently unperturbed levels yielded molecular constants as well as centrifugal distortion and spin-rotational constants for the upper state.