Knowledge Bank

The emission spectra of VN and VO have been investigated in the $3700-18300cm-1$ region using a Fourier transform spectrometer. The spectra of both these species were observed in the same experiment from the microwave excitation of $VOCl3$ vapor in active nitrogen. Several new bands were observed and assigned to new electronic transitions of VN and VO. For VN, two new electronic transitions were observed with their 0-0 bands near $14293cm-1$ and $5267cm-1$. These transitions have been assigned as the $c1\Pi -a1\Delta$ and $d1\Sigma +-b1\Sigma +$ transitions, respectively. The $d1\Sigma +$ state of VN is the only known singlet state to date which was seen previously from the $d1\Sigma +-X3\Delta 1$, transition near $16220cm-1$ by Simard et al. [J. Mol. Spectrosc. 136,44 (1989)]. For VO, the $12\Phi -12\Delta$ transition near $5545cm-1$ has been observed for the first time, although the $12\Phi$ and $12\Delta$ states have previously been seen by Merer et al. [J. Mol. Spectrosc. 125, 465, (1987)] from other transitions. A rotational analysis of the new bands provides valuable information on the low-lying electronic states of VN and VO.