Knowledge Bank

The flame reaction $Sr+N2O$ was investigated in a Broida-type oven by using laser excitation spectroscopy and dispersing the laser induced fluorescence with a 1/3m monochromator. The so far unclassified red and orange bands in the region 14700 to $15700cm-1$ and 16600 to $16900cm-1$[1] are undoubtedly attributed to Sr0 and partly share a common upper state. Laser excitation in the particularly congested spectrum near $16800cm-1$ with a cw dye laser of about 1 $cm-1$ linewidth leads to emission into the $X\prime \Sigma +$ ground state of SrO from two different states at 26360 and $26720cm-1$ above $\Sigma \prime \Sigma +(v\prime \prime =O)$. The spectrum around a separate bandhead at $16852cm-1$ was recorded at rotational resolution with a single mode laser. Fluorescence from the excited upper state of this system into the ground state, the well resolved A-doubling in the laser excitation spectra, and the determined rotational constants indicate that the lower state of this band is $a3\pi 1[1]$ and that the upper state should be a $\pi$ state.